1701:
2611:(SDI) program office, was an attempt to build a vehicle that could lead to an SSTO vehicle. The one-third-size test craft was operated and maintained by a small team of three people based out of a trailer, and the craft was once relaunched less than 24 hours after landing. Although the test program was not without mishap (including a minor explosion), the DC-X demonstrated that the maintenance aspects of the concept were sound. That project was cancelled when it landed with three of four legs deployed, tipped over, and exploded on the fourth flight after transferring management from the
300:
5068:
549:
2557:, a SSTO rocket launching an identical payload mass and using the same propellants will always require a substantially smaller structural coefficient to achieve the same delta-v. Given that current materials technology places a lower limit of approximately 0.1 on the smallest structural coefficients attainable, reusable SSTO vehicles are typically an impractical choice even when using the highest performance propellants available.
656:
33:
163:
858:
the payload/weight ratio of a single-stage rocket approach that of a two-stage. A slight miscalculation and the single-stage rocket winds up with no payload. To get any at all, technology needs to be stretched to the limit. Squeezing out the last drop of specific impulse, and shaving off the last pound, costs money and/or reduces reliability.
617:, using a vacuum bell in atmosphere would have disastrous consequences for the engine. Engines designed to fire in atmosphere therefore have to shorten the nozzle, only expanding the gasses to atmospheric pressure. The efficiency losses due to the smaller bell are usually mitigated via staging, as upper stage engines such as the
825:
in excess of 1, enabling them to lift off. Clearly, one of the main issues with nuclear propulsion would be safety, both during a launch for the passengers, but also in case of a failure during launch. As of
February 2024, no current program is attempting nuclear propulsion from Earth's surface.
741:
It is important to note that mass fraction is an important concept in the engineering of a rocket. However, mass fraction may have little to do with the costs of a rocket, as the costs of fuel are very small when compared to the costs of the engineering program as a whole. As a result, a cheap rocket
310:
The DC-X, short for Delta
Clipper Experimental, was an uncrewed one-third scale vertical takeoff and landing demonstrator for a proposed SSTO. It is one of only a few prototype SSTO vehicles ever built. Several other prototypes were intended, including the DC-X2 (a half-scale prototype) and the DC-Y,
857:
Using similar technologies (i.e., the same propellants and structural fraction), a two-stage-to-orbit vehicle will always have a better payload-to-weight ratio than a single stage designed for the same mission, in most cases, a very much better . Only when the structural factor approaches zero does
646:
Still, at very high altitudes, the extremely large engine bells tend to expand the exhaust gases down to near vacuum pressures. As a result, these engine bells are counterproductive due to their excess weight. Some SSTO concepts use very high pressure engines which permit high ratios to be used from
2695:
to prove the engines performance across its air-breathing and rocket modes. In
November 2012, it was announced that a key test of the engine precooler had been successfully completed, and that ESA had verified the precooler's design. The project's development is now allowed to advance to its next
2225:
1871:
687:
The thrust-to-weight ratio of rockets that rely on on-board oxygen increases dramatically as fuel is expended, because the oxidizer fuel tank has about 1% of the mass as the oxidizer it carries, whereas air-breathing engines traditionally have a poor thrust/weight ratio which is relatively fixed
511:
The overall effect is that there is surprisingly little difference in overall performance between SSTOs that use hydrogen and those that use denser fuels, except that hydrogen vehicles may be rather more expensive to develop and buy. Careful studies have shown that some dense fuels (for example
503:
as well; the vehicle has to hold itself up on rocket power until it reaches orbit. The lower excess thrust of the hydrogen engines due to the lower thrust/weight ratio means that the vehicle must ascend more steeply, and so less thrust acts horizontally. Less horizontal thrust results in taking
495:
While kerosene tanks can be 1% of the weight of their contents, hydrogen tanks often must weigh 10% of their contents. This is because of both the low density and the additional insulation required to minimize boiloff (a problem which does not occur with kerosene and many other fuels). The low
74:
The main projected advantage of the SSTO concept is elimination of the hardware replacement inherent in expendable launch systems. However, the non-recurring costs associated with design, development, research and engineering (DDR&E) of reusable SSTO systems are much higher than expendable
2741:
Using this concept, some aerospace analysts believe the way to lower launch costs is the exact opposite of SSTO. Whereas reusable SSTOs would reduce per launch costs by making a reusable high-tech vehicle that launches frequently with low maintenance, the "mass production" approach views the
496:
density of hydrogen further affects the design of the rest of the vehicle: pumps and pipework need to be much larger in order to pump the fuel to the engine. The result is the thrust/weight ratio of hydrogen-fueled engines is 30β50% lower than comparable engines using denser fuels.
1673:
82:
spacecraft from Earth. The principal complicating factors for SSTO from Earth are: high orbital velocity of over 7,400 metres per second (27,000 km/h; 17,000 mph); the need to overcome Earth's gravity, especially in the early stages of flight; and flight within
534:
experimental rocket has caused a number of SSTO advocates to reconsider hydrogen as a satisfactory fuel. The late Max Hunter, while employing hydrogen fuel in the DC-X, often said that he thought the first successful orbital SSTO would more likely be fueled by propane.
2742:
technical advances as a source of the cost problem in the first place. By simply building and launching large quantities of rockets, and hence launching a large volume of payload, costs can be brought down. This approach was attempted in the late 1970s, early 1980s in
840:
Because they can be more energetic than the potential energy that chemical fuel allows for, some laser or microwave powered rocket concepts have the potential to launch vehicles into orbit, single stage. In practice, this area is not possible with current technology.
400:
Whether rocket-powered or air-breathing, a reusable vehicle must be rugged enough to survive multiple round trips into space without adding excessive weight or maintenance. In addition a reusable vehicle must be able to reenter without damage, and land safely.
315:
in 1995, and they built the DC-XA, an upgraded one-third scale prototype. This vehicle was lost when it landed with only three of its four landing pads deployed, which caused it to tip over on its side and explode. The project has not been continued since.
613:. Depending on the atmospheric pressure, different bell shapes are required. Engines designed to operate in a vacuum have large bells, allowing the exhaust gasses to expand to near vacuum pressures, thereby raising efficiency. Due to an effect known as
192:
in the early 1960s. It was one of the largest spacecraft ever conceptualized with a diameter of over 50 metres and the capability to lift up to 2000 short tons into Earth orbit, intended for missions to further out locations in the Solar System such as
1280:
121:, which is a helicopter that can get to orbit. However, despite showing some promise, none of them have come close to achieving orbit yet due to problems with finding a sufficiently efficient propulsion system and discontinued development.
2403:
105:, which used the hybrid-cycle SABRE engine that can use oxygen from the atmosphere when it is at low altitude, and then using onboard liquid oxygen after switching to the closed cycle rocket engine at high altitude, the McDonnell Douglas
2011:
1704:
Comparison of growth factor sensitivity for Single-Stage-to-Orbit (SSTO) and restricted stage Two-Stage-to-Orbit (TSTO) vehicles. Based on a LEO mission of Delta v = 9.1 km/s and payload mass = 4500 kg for range of propellant
2069:
1711:
2306:
330:
From 1999 to 2001 Rotary Rocket attempted to build a SSTO vehicle called the Roton. It received a large amount of media attention and a working sub-scale prototype was completed, but the design was largely impractical.
124:
Single-stage-to-orbit is much easier to achieve on extraterrestrial bodies that have weaker gravitational fields and lower atmospheric pressure than Earth, such as the Moon and Mars, and has been achieved from the
2691:. Following a successful propulsion system test that was audited by ESA's propulsion division in mid-2012, REL announced that it would begin a three-and-a-half-year project to develop and build a test jig of the
204:
from 1963 was a similarly large craft which would have used ramjets to decrease the liftoff mass of the vehicle by removing the need for large amounts of liquid oxygen while traveling through the atmosphere.
1503:
75:
systems due to the substantial technical challenges of SSTO, assuming that those technical issues can in fact be solved. SSTO vehicles may also require a significantly higher degree of regular maintenance.
2549:
227:
ROMBUS (Reusable
Orbital Module, Booster, and Utility Shuttle), another design from Philip Bono. This was not technically single stage since it dropped some of its initial hydrogen tanks, but it came very
2062:
933:
404:
While single-stage rockets were once thought to be beyond reach, advances in materials technology and construction techniques have shown them to be possible. For example, calculations show that the
719:
Similar issues occur with single-stage vehicles attempting to carry conventional jet engines to orbitβthe weight of the jet engines is not compensated sufficiently by the reduction in propellant.
170:
Before the second half of the twentieth century, very little research was conducted into space travel. During the 1960s, some of the first concept designs for this kind of craft began to emerge.
2451:
1922:
813:
Due to weight issues such as shielding, many nuclear propulsion systems are unable to lift their own weight, and hence are unsuitable for launching to orbit. However, some designs such as the
750:
Many vehicles are only narrowly suborbital, so practically anything that gives a relatively small delta-v increase can be helpful, and outside assistance for a vehicle is therefore desirable.
1697:) is a critical parameter in SSTO vehicle design. Structural efficiency of a vehicle is maximized as the structural coefficient approaches zero. The structural coefficient is defined as:
201:
2486:
408:
first stage, launched on its own, would have a 25-to-1 ratio of fuel to vehicle hardware. It has a sufficiently efficient engine to achieve orbit, but without carrying much payload.
1158:
1123:
698:) and thrust levels of air-breathing jet engines drop considerably at high speed (above Mach 5β10 depending on the engine) and begin to approach that of rocket engines or worse.
1353:
1469:
993:
1165:
504:
longer to reach orbit, and gravity losses are increased by at least 300 metres per second (1,100 km/h; 670 mph). While not appearing large, the mass ratio to
1695:
960:
3049:
4375:
2492:(TSTO) vehicles for a standard LEO mission. The curves vertically asymptote at the maximum structural coefficient limit where mission criteria can no longer be met:
2315:
1496:
4001:
Mossman, Jason, "Investigation of
Advanced Propellants to Enable Single Stage to Orbit Launch Vehicles", Master's thesis, California State University, Fresno, 2006.
1440:
1411:
1382:
1311:
1026:
1081:
4204:
1929:
4354:
1055:
3658:
243:
Hyperion, yet another Philip Bono concept which used a sled to build up speed before liftoff to save on the amount of fuel which had to be lifted into the air.
389:
achieving a high enough mass-ratio to carry sufficient propellant to achieve orbit, plus a meaningful payload weight. Air-breathing designs typically fly at
4010:
Livington, J.W., "Comparative
Analysis of Rocket and Air-Breathing Launch Vehicle Systems", Space 2004 Conference and Exhibit, San Diego, California, 2004.
3550:
2220:{\displaystyle 1={\frac {m_{\text{pl}}}{m_{i}}}+{\frac {m_{p}}{m_{i}}}+{\frac {m_{s}}{m_{i}}}={\frac {m_{\text{pl}}}{m_{i}}}+\zeta +{\frac {m_{s}}{m_{i}}}}
1866:{\displaystyle \lambda ={\frac {m_{s}}{m_{p}+m_{s}}}={\frac {m_{s}}{m_{i}-m_{\text{pl}}}}={\frac {\frac {m_{s}}{m_{i}}}{1-{\frac {m_{\text{pl}}}{m_{i}}}}}}
60:
from the surface of a body using only propellants and fluids and without expending tanks, engines, or other major hardware. The term exclusively refers to
3958:
3521:
2488:, the size of a vehicle increases with an increasing structural coefficient. This growth factor sensitivity is shown parametrically for both SSTO and
2777:
64:. To date, no Earth-launched SSTO launch vehicles have ever been flown; orbital launches from Earth have been performed by either fully or partially
3594:
3026:
2231:
742:
with a poor mass fraction may be able to deliver more payload to orbit with a given amount of money than a more complicated, more efficient rocket.
4402:
311:
a full-scale vehicle which would be capable of single stage insertion into orbit. Neither of these were built, but the project was taken over by
508:
curve is very steep to reach orbit in a single stage, and this makes a 10% difference to the mass ratio on top of the tankage and pump savings.
231:
Ithacus, an adapted ROMBUS concept which was designed to carry soldiers and military equipment to other continents via a sub-orbital trajectory.
4798:
4095:
277:
project was intended to launch a scramjet vehicle into orbit, but funding was stopped and the project cancelled. At around the same time, the
4916:
3901:
3894:
2951:
2944:
3933:
4537:
3302:
2718:, has the capability to reach orbit as an SSTO. However he concedes that if this was done, there would be no appreciable mass left for a
4266:
3942:
AIAA, Joint
Propulsion Conference, 21st, Monterey, CA, 8β11 July 1985. 10 p. Research supported by the Rensselaer Polytechnic Institute.
1668:{\displaystyle \zeta ={\frac {m_{p}}{m_{i}}}={\frac {m_{i}-m_{f}}{m_{i}}}=1-{\frac {m_{f}}{m_{i}}}=1-{\frac {1}{MR}}={\frac {MR-1}{MR}}}
4021:
3272:
738:
over pure rockets (even multistage rockets) sufficiently to hold out the possibility of full reusability with better payload fraction.
4296:
3738:
2757:
This is somewhat similar to the approach some previous systems have taken, using simple engine systems with "low-tech" fuels, as the
2612:
2497:
234:
Pegasus, another adapted ROMBUS concept designed to carry passengers and payloads long distances in short amounts of time via space.
4814:
4241:
734:) which transition to rocket thrust at rather lower speeds (Mach 5.5) do seem to give, on paper at least, an improved orbital
90:
Advances in rocketry in the 21st century have resulted in a substantial fall in the cost to launch a kilogram of payload to either
2018:
3544:"Star Raker An Airbreather/Rocket-Powered, Horizontal Takeoff Tridelta Flying Wing, Single-Stage-to-Orbit Transportation System"
570:
4181:
871:
4363:
691:
Very high speeds in the atmosphere necessitate very heavy thermal protection systems, which makes reaching orbit even harder.
4147:
4117:
3684:
3234:
677:
No known air breathing engine is capable of operating at orbital speed within the atmosphere (for example hydrogen fueled
4395:
3458:
3414:
3208:
2762:
2410:
1878:
4061:
3392:
3370:
3325:
3070:
2407:
This expression shows how the size of a SSTO vehicle is dependent on its structural efficiency. Given a mission profile
2015:
An additional expression for the overall structural mass fraction can be found by noting that the payload mass fraction
628:, which can be effective in a wide range of ambient pressures. In fact, a linear aerospike engine was to be used in the
609:
Some SSTO concepts use the same engine for all altitudes, which is a problem for traditional engines with a bell-shaped
339:
There have been various approaches to SSTO, including pure rockets that are launched and land vertically, air-breathing
4719:
4212:
3347:
814:
344:
4351:
3760:
3483:
3186:
681:
seem to have a top speed of about Mach 17). This means that rockets must be used for the final orbital insertion.
4793:
4318:
3117:
2917:
704:
of vehicles at hypersonic speeds are poor, however the effective lift to drag ratios of rocket vehicles at high g is
596:
3979:
London III, Lt Col John R., "LEO on the Cheap", Air
University (AFMC) Research Report No. AU-ARI-93-8, October 1994.
3650:
2979:
Dick, Stephen and
Lannius, R., "Critical Issues in the History of Spaceflight," NASA Publication SP-2006-4702, 2006.
578:
266:
satellites into a 300 nautical mile Earth orbit. Star-raker would have had 3 x LOX/LH2 rocket engines (based on the
3436:
3160:
2747:
3130:
3867:
3816:
3575:
3543:
2456:
5112:
5092:
4819:
4684:
4388:
2730:
Many studies have shown that regardless of selected technology, the most effective cost reduction technique is
2688:
574:
3954:
1090:
The mass ratio of a vehicle is defined as a ratio the initial vehicle mass when fully loaded with propellants
516:) exceed the performance of hydrogen fuel when used in an SSTO launch vehicle by 10% for the same dry weight.
4923:
4778:
4747:
4742:
363:
3513:
3711:
2711:
2608:
636:
670:
that collect oxidizer and reaction mass from the atmosphere to reduce the take-off weight of the vehicle.
438:
Hydrogen has nearly 30% higher specific impulse (about 450 seconds vs. 350 seconds) than most dense fuels.
4035:
3098:. Ames Mission Analysis Division Office of Advanced Research and Technology: NASA. p. 54. N93-71495.
863:
385:, and construction techniques necessary for surviving sustained high-speed flight within the atmosphere,
95:
3610:
2734:. Merely launching a large total number reduces the manufacturing costs per vehicle, similar to how the
1128:
1093:
5097:
2310:
Equating the expressions for structural mass fraction and solving for the initial vehicle mass yields:
1319:
354:
For rocket-powered SSTO, the main challenge is achieving a high enough mass-ratio to carry sufficient
173:
One of the earliest SSTO concepts was the expendable One stage
Orbital Space Truck (OOST) proposed by
4878:
4737:
3077:
621:
do not have to fire until atmospheric pressure is negligible, and can therefore use the larger bell.
267:
223:
Further examples of Bono's early concepts (prior to the 1990s) which were never constructed include:
4087:
3955:"High-elevation equatorial catapult-launched RBCC SSTO spaceplane for economic manned access to LEO"
2687:
was canceled. The Skylon spaceplane has been positively received by the British government, and the
4911:
4670:
4644:
4586:
4570:
4560:
2840:
2676:
1475:
1447:
971:
735:
559:
485:
378:
178:
87:, which limits speed in the early stages of flight due to drag, and influences engine performance.
65:
4843:
3905:
3326:"ROMBUS - An Integrated Systems Concept for a Reusable Orbital Module/Booster And Utility Shuttle"
2955:
2588:) was an enormous vehicle with more than 50,000 kilograms (110,000 lb) of payload, utilizing
1275:{\displaystyle MR={\frac {m_{i}}{m_{f}}}={\frac {m_{p}+m_{s}+m_{\text{pl}}}{m_{s}+m_{\text{pl}}}}}
351:-powered vehicles that can fly into orbit and return landing like an airliner, completely intact.
5107:
4967:
4940:
4895:
4883:
4863:
4629:
4591:
4565:
2820:
2655:
2619:
2593:
835:
727:
667:
563:
348:
263:
255:
79:
5018:
4868:
4768:
4510:
4263:
2769:
2565:
It is easier to achieve SSTO from a body with lower gravitational pull than Earth, such as the
2398:{\displaystyle m_{i}=GLOW={\frac {m_{\text{pl}}}{1-\left({\frac {\zeta }{1-\lambda }}\right)}}}
1314:
822:
818:
304:
294:
251:
106:
61:
3294:
1680:
942:
684:
Rocket thrust needs the orbital mass to be as small as possible to minimize propellant weight.
5102:
4603:
4596:
4411:
3734:
2875:
2692:
2665:
189:
3264:
2006:{\displaystyle {\frac {m_{s}}{m_{i}}}=\lambda \left(1-{\frac {m_{\text{pl}}}{m_{i}}}\right)}
1481:
4714:
4709:
4613:
4527:
3002:
2880:
2835:
2758:
2680:
2581:
1418:
1389:
1360:
1289:
1004:
779:
723:
629:
524:
282:
110:
17:
4288:
4237:
3841:
1066:
444:
The gross mass of hydrogen stages is lower than dense-fuelled stages for the same payload.
8:
4873:
4858:
4773:
4660:
4639:
4608:
2815:
2672:
2643:
2574:
659:
647:
ground level. This gives good performance, negating the need for more complex solutions.
134:
102:
84:
3006:
2910:
Single Stage to Orbit - Politics, Space Technology, and the Quest for Reusable Rocketry.
1037:
5072:
5038:
5003:
3790:
2885:
2731:
2489:
849:
The design space constraints of SSTO vehicles were described by rocket design engineer
808:
761:
757:
701:
3624:
2990:
5067:
5033:
4988:
4888:
4788:
4490:
4464:
3602:
3113:
3018:
3014:
2913:
2895:
2696:
phase, which involves the construction and testing of a full-scale prototype engine.
2604:
2554:
1084:
694:
While at lower speeds, air-breathing engines are very efficient, but the efficiency (
68:
3930:
2719:
478:
Wide combustible range β easily ignited and burns with a dangerously invisible flame
5053:
5043:
4993:
4699:
4452:
3242:
3010:
2810:
1029:
996:
695:
640:
625:
427:
of any commonly used fuel: around 450 seconds, compared with up to 350 seconds for
424:
405:
382:
213:
299:
254:
unveiled a concept for a 100-ton payload heavy-lift multicycle airbreather ramjet/
4665:
4469:
4435:
4358:
4270:
4151:
3937:
3081:
2789:
2735:
2715:
2705:
614:
91:
4369:
2592:
for (vertical) landing. While the technical problems seemed to be solvable, the
4998:
4933:
4634:
4474:
4125:
3680:
3491:
2870:
2751:
2584:'s Space Division in 1970β1971 under NASA contract NAS8-26341. Their proposal (
1700:
783:
618:
377:
For air-breathing SSTO, the main challenge is system complexity and associated
258:, horizontal takeoff/horizontal landing single-stage-to-orbit spaceplane named
237:
185:
138:
130:
3601:, vol. 129, no. 4000, Business Press International, pp. 38β40,
3466:
3422:
3212:
2301:{\displaystyle {\frac {m_{s}}{m_{i}}}=1-\zeta -{\frac {m_{\text{pl}}}{m_{i}}}}
866:
expresses the maximum change in velocity any single rocket stage can achieve:
285:
technology, but failed to show significant advantages over rocket technology.
5086:
5008:
4928:
4783:
4752:
4532:
4522:
4517:
4440:
4430:
4065:
3606:
3400:
3378:
3333:
3022:
2860:
2855:
2773:
2635:
416:
325:
274:
217:
118:
78:
It is considered to be marginally possible to launch a single-stage-to-orbit
3355:
208:
From 1965, Robert Salkeld investigated various single stage to orbit winged
5013:
4972:
4945:
4704:
4500:
4495:
3768:
3371:""Ithacus" β a new concept of inter-continental ballistic transport (ICBT)"
3182:
2850:
2785:
2743:
2585:
850:
793:
705:
500:
146:
142:
4326:
3134:
2991:"Cost analysis for single-stage (SSTO) reusable ballistic launch vehicles"
397:
speeds, and usually include a rocket engine for the final burn for orbit.
5028:
5023:
4829:
3871:
3514:"The Space Plane NASA Wanted to Use to Build Solar Power Plants in Orbit"
2890:
2830:
2825:
2793:
2631:
520:
472:β must be stored at very low temperatures and thus needs heavy insulation
371:
174:
114:
37:
4380:
3444:
3156:
1498:) of a vehicle can be expressed solely as a function of the mass ratio:
5048:
4505:
2668:
2639:
2589:
1058:
771:
394:
390:
355:
209:
41:
2622:
was designed to bring bulk materials to orbit as cheaply as possible.
2596:
required a winged design that led to the Shuttle as we know it today.
366:
weight. One possibility is to give the rocket an initial speed with a
3579:
2845:
2797:
713:
469:
367:
4173:
2768:
An alternative to scale is to make the discarded stages practically
2725:
2064:, propellant mass fraction and structural mass fraction sum to one:
548:
4366:, an analysis of space launch costs, with a section critiquing SSTO
2865:
2781:
765:
678:
428:
340:
3895:"A Comparison of Propulsions Concepts for SSTO Reusable launchers"
3050:"DEPLOYED PAYLOAD ANALYSIS FOR A SINGLE STAGE TO ORBIT SPACEPLANE"
2577:
ascended from the lunar surface to lunar orbit in a single stage.
4824:
4457:
2945:"A Comparison of Propulsion Concepts for SSTO Reusable Launchers"
963:
513:
505:
3209:"Encyclopedia Astronautica - North American Air Augmented VTOVL"
655:
419:
might seem the obvious fuel for SSTO vehicles. When burned with
4447:
4425:
3931:"Transatmospheric vehicle propelled by air-turborocket engines"
3929:
Cimino, P.; Drake, J.; Jones, J.; Strayer, D.; Venetoklis, P.:
2738:
of automobiles brought about great increases in affordability.
2722:, landing legs, or fuel to land, much less any usable payload.
610:
527:, and showed that it could improve payload size by around 30%.
420:
184:
Another early SSTO concept was a reusable launch vehicle named
32:
3586:
2544:{\displaystyle \lambda _{\text{max}}=1-\zeta ={\frac {1}{MR}}}
481:
Tends to condense oxygen which can cause flammability problems
3707:
2684:
731:
359:
278:
98:, reducing the main projected advantage of the SSTO concept.
57:
716:) the mass budgets do not seem to close for orbital launch.
2600:
2570:
2566:
2057:{\displaystyle \left({\frac {m_{\text{pl}}}{m_{i}}}\right)}
531:
343:-powered vehicles that are launched and land horizontally,
312:
194:
126:
3074:
4238:"Skylon spaceplane engine concept achieves key milestone"
2661:
1924:
can be expressed in terms of the structural coefficient:
635:
Other solutions involve using multiple engines and other
465:
of the density of kerosene) β requiring a very large tank
162:
117:
which was intended to replace the Space Shuttle, and the
3892:
2942:
2630:
Current and previous SSTO projects include the Japanese
928:{\displaystyle \Delta v=I_{\text{sp}}\cdot g_{0}\ln(MR)}
3705:
3057:
Centre for Future Air Space Transportation Technologies
4148:"UK Space Agency - Skylon System Requirements Review"
2500:
2459:
2413:
2318:
2234:
2072:
2021:
1932:
1881:
1714:
1683:
1506:
1484:
1450:
1421:
1392:
1363:
1322:
1292:
1168:
1131:
1096:
1069:
1040:
1007:
974:
945:
874:
844:
4264:"European Space Agency clears SABRE orbital engines"
2912:
The Johns Hopkins University Press, Baltimore 2004,
2580:
A detailed study into SSTO vehicles was prepared by
2553:
In comparison to a non-optimized TSTO vehicle using
181:. A reusable version named ROOST was also proposed.
4232:
4230:
4118:"Reaction Engines Ltd - Frequently Asked Questions"
3625:"Wired 4.05: Insanely Great? or Just Plain Insane?"
3613:
on 22 October 2012 – via FlightGlobal Archive
3478:
3476:
2446:{\displaystyle \left(\Delta v,m_{\text{pl}}\right)}
1917:{\displaystyle \left({\frac {m_{s}}{m_{i}}}\right)}
966:) is the maximum change of velocity of the vehicle,
492:These issues can be dealt with, but at extra cost.
2543:
2480:
2445:
2397:
2300:
2219:
2056:
2005:
1916:
1865:
1689:
1667:
1490:
1463:
1434:
1405:
1376:
1347:
1305:
1274:
1152:
1117:
1075:
1049:
1020:
987:
954:
927:
3071:"The Recent Large Reduction in Space Launch Cost"
2778:SpaceX reusable launch system development program
2776:phase B studies, and is currently pursued by the
2726:Alternative approaches to inexpensive spaceflight
2603:technology demonstrator, originally developed by
212:concepts. He proposed a vehicle which would burn
5084:
4227:
4202:
4166:
4088:"UKSA Reviews Skylon and SABRE at Parabolic Arc"
3473:
451:However, hydrogen also has these disadvantages:
4025:, Third Edition, Oxford: Elsevier, 2010. Print.
2710:Elon Musk, CEO of SpaceX, has claimed that the
538:
101:Notable single stage to orbit concepts include
4376:Burnout Velocity Vb of a Single 1-Stage Rocket
3732:
2712:upper stage of the prototype "Starship" rocket
411:
137:, by several robotic spacecraft of the Soviet
4396:
3902:Journal of the British Interplanetary Society
712:Thus with for example scramjet designs (e.g.
27:Launch system that only uses one rocket stage
4205:"SSTO spaceplane is coming to Great Britain"
3886:
3651:"A Cannon for Shooting Supplies into Space"
3317:
3133:. Encyclopedia Astronautica. Archived from
2772:: this was the original design goal of the
673:Some of the issues with this approach are:
577:. Unsourced material may be challenged and
216:while in the atmosphere and then switch to
4403:
4389:
4352:A Single-Stage-to-Orbit Thought Experiment
4022:Orbital Mechanics for Engineering Students
3735:"Alternate Propellants for SSTO Launchers"
2938:
2936:
2934:
2660:The British Government partnered with the
2481:{\displaystyle \left(I_{\text{sp}}\right)}
829:
4410:
4059:
3865:
3706:Mitchell Burnside-Clapp (February 1997).
3108:Philip Bono and Kenneth William Gatland,
2613:Strategic Defense Initiative Organization
1384:is the final vehicle mass after the burn,
624:One possible solution would be to use an
597:Learn how and when to remove this message
475:Escapes very easily from the smallest gap
220:for increasing efficiency once in space.
4815:Atmosphere-breathing electric propulsion
4196:
3893:Richard Varvill & Alan Bond (2003).
2943:Richard Varvill & Alan Bond (2003).
1699:
654:
298:
161:
31:
3096:A Single Stage To Orbit Shuttle Concept
2931:
434:Hydrogen has the following advantages:
14:
5085:
4372:A critique of SSTO by Jeffrey F. Bell.
3814:
2988:
2625:
4384:
4203:Robert Parkinson (22 February 2011).
3741:from the original on 26 February 2014
3592:
3556:from the original on 29 February 2020
1875:The overall structural mass fraction
802:
666:Some designs for SSTO attempt to use
499:This inefficiency indirectly affects
447:Hydrogen is environmentally friendly.
4286:
4184:from the original on 8 November 2011
3368:
3323:
3183:"SP-4221 The Space Shuttle Decision"
650:
575:adding citations to reliable sources
542:
4244:from the original on 1 October 2021
3961:from the original on 1 October 2021
3714:from the original on 1 October 2021
3708:"A LO2/Kerosene SSTO Rocket Design"
3687:from the original on 1 October 2021
3305:from the original on 1 October 2021
3189:from the original on 1 October 2021
3163:from the original on 1 October 2021
3029:from the original on 1 October 2021
2989:Koelle, Dietrich E. (1 July 1993).
1313:is the initial vehicle mass or the
24:
4720:Field-emission electric propulsion
3904:. pp. 108β117. Archived from
3524:from the original on 7 August 2020
3094:Gomersall, Edward (20 July 1970).
2902:
2419:
1413:is the structural mass of vehicle,
1153:{\displaystyle \left(m_{f}\right)}
1118:{\displaystyle \left(m_{i}\right)}
946:
875:
845:Design challenges inherent in SSTO
288:
202:North American Air Augmented VTOVL
25:
5124:
4794:Microwave electrothermal thruster
4370:The Cold Equations Of Spaceflight
4345:
4098:from the original on 14 June 2015
3275:from the original on 11 June 2019
1348:{\displaystyle \left(GLOW\right)}
753:Proposed launch assists include:
745:
441:Hydrogen is an excellent coolant.
157:
5066:
4299:from the original on 5 June 2021
4036:"Apollo 11 Lunar Module / EASEP"
3842:"SABRE :: Reaction Engines"
3815:Monroe, Conner (30 March 2016).
3661:from the original on 15 May 2021
3578:. 29 August 2002. Archived from
3128:
3047:
2748:Democratic Republic of the Congo
789:And on-orbit resources such as:
688:during the air-breathing ascent.
547:
530:Operational experience with the
523:investigated single-stage, VTVL
240:, a 1967 launch vehicle concept.
4311:
4280:
4256:
4140:
4110:
4080:
4053:
4028:
4013:
4004:
3995:
3982:
3973:
3947:
3923:
3859:
3834:
3808:
3783:
3753:
3726:
3699:
3673:
3643:
3617:
3568:
3536:
3506:
3451:
3429:
3407:
3385:
3377:(AIAA-1964-280). Archived from
3362:
3340:
3332:(AIAA-1963-271). Archived from
3287:
3257:
3227:
3201:
3175:
2675:. This design was pioneered by
4924:Pulsed nuclear thermal rocketβ
4820:High Power Electric Propulsion
3593:Moxon, Julian (1 March 1986),
3149:
3122:
3102:
3087:
3063:
3041:
2982:
2973:
2714:, currently in development in
2689:British Interplanetary Society
2677:Reaction Engines Limited (REL)
922:
913:
149:lunar sample return missions.
13:
1:
4779:Helicon double-layer thruster
4748:Electrodeless plasma thruster
4743:Magnetoplasmadynamic thruster
4364:Why are launch costs so high?
3084:. Retrieved 12 December 2018.
2924:
1464:{\displaystyle m_{\text{pl}}}
988:{\displaystyle I_{\text{sp}}}
722:On the other hand, LACE-like
423:, hydrogen gives the highest
334:
3990:Introduction to Space Flight
3093:
3015:10.1016/0094-5765(93)90132-G
2609:Strategic Defense Initiative
1677:The structural coefficient (
539:One engine for all altitudes
7:
2803:
2699:
2560:
864:Tsiolkovsky rocket equation
639:such as double-mu bells or
412:Dense versus hydrogen fuels
262:, designed to launch heavy
96:International Space Station
10:
5129:
4287:Musk, Elon (5 June 2021).
4174:"Reaction Engines Limited"
3369:Bono, Philip (June 1963).
3324:Bono, Philip (June 1963).
2703:
2653:
1125:to the final vehicle mass
833:
806:
772:air launch or aircraft tow
488:for even small heat leaks.
323:
292:
152:
5064:
4981:
4960:
4904:
4851:
4842:
4807:
4761:
4738:Pulsed inductive thruster
4730:
4692:
4683:
4653:
4622:
4579:
4553:
4546:
4483:
4418:
4240:. BBC. 28 November 2012.
3846:www.reactionengines.co.uk
3157:Aerospace projects Review
2649:
637:altitude adapting designs
303:The maiden flight of the
4912:Nuclear pulse propulsion
4671:Electric-pump-fed engine
4571:Hybrid-propellant rocket
4561:Liquid-propellant rocket
1690:{\displaystyle \lambda }
1476:propellant mass fraction
955:{\displaystyle \Delta v}
760:(rail, maglev including
668:airbreathing jet engines
641:extensible bell sections
486:coefficient of expansion
455:Very low density (about
379:research and development
319:
179:Douglas Aircraft Company
4968:Beam-powered propulsion
4941:Fission-fragment rocket
4896:Nuclear photonic rocket
4864:Nuclear electric rocket
4630:Staged combustion cycle
4566:Solid-propellant rocket
3733:Dr. Bruce Dunn (1996).
3295:"STS-1 Further Reading"
3159:(Report). Vol. 3.
3069:Harry W. Jones (2018).
2821:British Aerospace HOTOL
2679:, a company founded by
2656:Reaction Engines Skylon
2620:Aquarius Launch Vehicle
1442:is the propellant mass,
836:Beam-powered propulsion
830:Beam-powered propulsion
270:) + 10 x turboramjets.
264:Space-based solar power
256:cryogenic rocket engine
5019:Non-rocket spacelaunch
4869:Nuclear thermal rocket
4769:Pulsed plasma thruster
4289:"Elon Musk on Twitter"
4269:1 October 2021 at the
3992:, Prentice Hall, 1994.
3936:1 October 2021 at the
3817:"Lockheed Martin X-33"
2763:Chinese space programs
2545:
2482:
2447:
2399:
2302:
2221:
2058:
2007:
1918:
1867:
1706:
1691:
1669:
1492:
1491:{\displaystyle \zeta }
1465:
1436:
1407:
1378:
1349:
1307:
1276:
1154:
1119:
1077:
1051:
1022:
989:
956:
929:
860:
823:thrust to weight ratio
724:precooled airbreathing
663:
307:
295:McDonnell Douglas DC-X
252:Rockwell International
188:which was proposed by
167:
45:
5113:Spacecraft propulsion
5093:Single-stage-to-orbit
4685:Electrical propulsion
4412:Spacecraft propulsion
4178:reactionengines.co.uk
4122:reactionengines.co.uk
4094:. 22 September 2010.
3080:15 March 2020 at the
2876:Spacecraft propulsion
2666:single-stage to orbit
2664:in 2010 to promote a
2546:
2483:
2448:
2400:
2303:
2222:
2059:
2008:
1919:
1868:
1703:
1692:
1670:
1493:
1466:
1437:
1435:{\displaystyle m_{p}}
1408:
1406:{\displaystyle m_{s}}
1379:
1377:{\displaystyle m_{f}}
1350:
1308:
1306:{\displaystyle m_{i}}
1277:
1155:
1120:
1078:
1052:
1023:
1021:{\displaystyle g_{0}}
990:
957:
930:
855:
658:
525:tripropellant rockets
302:
190:Krafft Arnold Ehricke
165:
50:single-stage-to-orbit
35:
4917:Antimatter-catalyzed
4715:Hall-effect thruster
4528:Solar thermal rocket
4357:15 June 2021 at the
4154:on 26 September 2010
3599:Flight International
3595:"Hotol: where next?"
3381:on 16 December 2008.
3336:on 16 December 2008.
2881:Three-stage-to-orbit
2836:Lockheed Martin X-33
2582:Chrysler Corporation
2498:
2457:
2453:and propellant type
2411:
2316:
2232:
2070:
2019:
1930:
1879:
1712:
1681:
1504:
1482:
1471:is the payload mass.
1448:
1419:
1390:
1361:
1320:
1315:gross liftoff weight
1290:
1166:
1129:
1094:
1076:{\displaystyle \ln }
1067:
1038:
1005:
972:
943:
872:
780:Lofstrom launch loop
726:designs such as the
571:improve this section
370:, as planned in the
362:, plus a meaningful
283:precooled jet engine
111:Lockheed Martin X-33
40:was a proposed SSTO
4859:Direct Fusion Drive
4774:Vacuum arc thruster
4661:Pressure-fed engine
4640:Gas-generator cycle
4547:Chemical propulsion
4484:Physical propulsion
4323:www.astronautix.com
4277:. 29 November 2012.
4215:on 23 February 2011
4040:nssdc.gsfc.nasa.gov
3657:. 15 January 2010.
3488:www.astronautix.com
3463:www.astronautix.com
3441:www.astronautix.com
3419:www.astronautix.com
3397:www.astronautix.com
3352:www.astronautix.com
3245:on 28 December 2016
3007:1993AcAau..30..415K
2908:Andrew J. Butrica:
2816:Bristol Spaceplanes
2626:Current development
2575:Apollo Lunar Module
702:Lift to drag ratios
347:vehicles, and even
69:multi-stage rockets
5073:Spaceflight portal
5039:Reactionless drive
5004:Aerogravity assist
4844:Nuclear propulsion
4060:Mark Wade (2007).
3866:Mark Wade (2007).
3681:"The titan family"
3582:on 29 August 2002.
3447:on 6 October 2008.
3265:"ROBERT SALKELD'S"
3137:on 10 October 2011
3110:Frontiers of Space
2886:Two-stage-to-orbit
2732:economies of scale
2555:restricted staging
2541:
2490:two-stage-to-orbit
2478:
2443:
2395:
2298:
2217:
2054:
2003:
1914:
1863:
1707:
1687:
1665:
1488:
1461:
1432:
1403:
1374:
1345:
1303:
1272:
1150:
1115:
1073:
1050:{\displaystyle MR}
1047:
1018:
995:is the propellant
985:
952:
925:
821:designs do have a
809:Nuclear propulsion
803:Nuclear propulsion
664:
308:
177:, an engineer for
168:
166:ROMBUS concept art
85:Earth's atmosphere
56:) vehicle reaches
46:
5098:Rocket propulsion
5080:
5079:
5034:Atmospheric entry
4989:Orbital mechanics
4956:
4955:
4838:
4837:
4789:Resistojet rocket
4679:
4678:
4654:Intake mechanisms
4587:Liquid propellant
4491:Cold gas thruster
4329:on 1 October 2021
4209:The Global Herald
3874:on 29 August 2002
3235:"Salkeld Shuttle"
2995:Acta Astronautica
2896:XS-1 (spacecraft)
2605:McDonnell Douglas
2539:
2508:
2471:
2435:
2393:
2386:
2356:
2296:
2283:
2257:
2215:
2182:
2169:
2155:
2128:
2101:
2088:
2048:
2035:
1996:
1983:
1955:
1908:
1861:
1858:
1845:
1828:
1800:
1796:
1758:
1663:
1634:
1610:
1577:
1535:
1458:
1270:
1266:
1241:
1200:
1085:natural logarithm
982:
891:
776:in-flight fueling
762:Bantam, MagLifter
728:Skylon spaceplane
651:Airbreathing SSTO
607:
606:
599:
141:, and by China's
80:chemically fueled
62:reusable vehicles
16:(Redirected from
5120:
5070:
5054:Alcubierre drive
5044:Field propulsion
4994:Orbital maneuver
4982:Related concepts
4849:
4848:
4700:Colloid thruster
4690:
4689:
4551:
4550:
4453:Specific impulse
4405:
4398:
4391:
4382:
4381:
4339:
4338:
4336:
4334:
4325:. Archived from
4315:
4309:
4308:
4306:
4304:
4284:
4278:
4260:
4254:
4253:
4251:
4249:
4234:
4225:
4224:
4222:
4220:
4211:. Archived from
4200:
4194:
4193:
4191:
4189:
4170:
4164:
4163:
4161:
4159:
4150:. Archived from
4144:
4138:
4137:
4135:
4133:
4124:. Archived from
4114:
4108:
4107:
4105:
4103:
4092:parabolicarc.com
4084:
4078:
4077:
4075:
4073:
4064:. Archived from
4057:
4051:
4050:
4048:
4046:
4032:
4026:
4019:Curtis, Howard,
4017:
4011:
4008:
4002:
3999:
3993:
3986:
3980:
3977:
3971:
3970:
3968:
3966:
3951:
3945:
3927:
3921:
3920:
3918:
3916:
3910:
3899:
3890:
3884:
3883:
3881:
3879:
3870:. Archived from
3863:
3857:
3856:
3854:
3852:
3838:
3832:
3831:
3829:
3827:
3812:
3806:
3805:
3803:
3801:
3795:www.grc.nasa.gov
3787:
3781:
3780:
3778:
3776:
3767:. Archived from
3757:
3751:
3750:
3748:
3746:
3730:
3724:
3723:
3721:
3719:
3703:
3697:
3696:
3694:
3692:
3677:
3671:
3670:
3668:
3666:
3647:
3641:
3640:
3638:
3636:
3621:
3615:
3614:
3609:, archived from
3590:
3584:
3583:
3572:
3566:
3565:
3563:
3561:
3555:
3548:
3540:
3534:
3533:
3531:
3529:
3510:
3504:
3503:
3501:
3499:
3494:on 7 August 2020
3490:. Archived from
3480:
3471:
3470:
3465:. Archived from
3455:
3449:
3448:
3443:. Archived from
3433:
3427:
3426:
3425:on 3 March 2016.
3421:. Archived from
3411:
3405:
3404:
3399:. Archived from
3389:
3383:
3382:
3366:
3360:
3359:
3358:on 11 June 2008.
3354:. Archived from
3344:
3338:
3337:
3321:
3315:
3314:
3312:
3310:
3291:
3285:
3284:
3282:
3280:
3261:
3255:
3254:
3252:
3250:
3241:. Archived from
3231:
3225:
3224:
3222:
3220:
3211:. Archived from
3205:
3199:
3198:
3196:
3194:
3185:. NASA History.
3179:
3173:
3172:
3170:
3168:
3153:
3147:
3146:
3144:
3142:
3126:
3120:
3106:
3100:
3099:
3091:
3085:
3067:
3061:
3060:
3054:
3048:Toso, Federico.
3045:
3039:
3038:
3036:
3034:
2986:
2980:
2977:
2971:
2970:
2968:
2966:
2960:
2954:. Archived from
2949:
2940:
2811:Aerospike engine
2716:Starbase (Texas)
2550:
2548:
2547:
2542:
2540:
2538:
2527:
2510:
2509:
2506:
2487:
2485:
2484:
2479:
2477:
2473:
2472:
2469:
2452:
2450:
2449:
2444:
2442:
2438:
2437:
2436:
2433:
2404:
2402:
2401:
2396:
2394:
2392:
2391:
2387:
2385:
2371:
2358:
2357:
2354:
2348:
2328:
2327:
2307:
2305:
2304:
2299:
2297:
2295:
2294:
2285:
2284:
2281:
2275:
2258:
2256:
2255:
2246:
2245:
2236:
2226:
2224:
2223:
2218:
2216:
2214:
2213:
2204:
2203:
2194:
2183:
2181:
2180:
2171:
2170:
2167:
2161:
2156:
2154:
2153:
2144:
2143:
2134:
2129:
2127:
2126:
2117:
2116:
2107:
2102:
2100:
2099:
2090:
2089:
2086:
2080:
2063:
2061:
2060:
2055:
2053:
2049:
2047:
2046:
2037:
2036:
2033:
2027:
2012:
2010:
2009:
2004:
2002:
1998:
1997:
1995:
1994:
1985:
1984:
1981:
1975:
1956:
1954:
1953:
1944:
1943:
1934:
1923:
1921:
1920:
1915:
1913:
1909:
1907:
1906:
1897:
1896:
1887:
1872:
1870:
1869:
1864:
1862:
1860:
1859:
1857:
1856:
1847:
1846:
1843:
1837:
1827:
1826:
1817:
1816:
1807:
1806:
1801:
1799:
1798:
1797:
1794:
1785:
1784:
1774:
1773:
1764:
1759:
1757:
1756:
1755:
1743:
1742:
1732:
1731:
1722:
1696:
1694:
1693:
1688:
1674:
1672:
1671:
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1664:
1662:
1654:
1640:
1635:
1633:
1622:
1611:
1609:
1608:
1599:
1598:
1589:
1578:
1576:
1575:
1566:
1565:
1564:
1552:
1551:
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1536:
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1533:
1524:
1523:
1514:
1497:
1495:
1494:
1489:
1470:
1468:
1467:
1462:
1460:
1459:
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1441:
1439:
1438:
1433:
1431:
1430:
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1383:
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1380:
1375:
1373:
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1346:
1344:
1340:
1312:
1310:
1309:
1304:
1302:
1301:
1281:
1279:
1278:
1273:
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1269:
1268:
1267:
1264:
1255:
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1244:
1243:
1242:
1239:
1230:
1229:
1217:
1216:
1206:
1201:
1199:
1198:
1189:
1188:
1179:
1160:after the burn:
1159:
1157:
1156:
1151:
1149:
1145:
1144:
1124:
1122:
1121:
1116:
1114:
1110:
1109:
1082:
1080:
1079:
1074:
1056:
1054:
1053:
1048:
1030:standard gravity
1027:
1025:
1024:
1019:
1017:
1016:
997:specific impulse
994:
992:
991:
986:
984:
983:
980:
961:
959:
958:
953:
934:
932:
931:
926:
906:
905:
893:
892:
889:
626:aerospike engine
602:
595:
591:
588:
582:
551:
543:
464:
463:
459:
425:specific impulse
383:material science
273:Around 1985 the
214:hydrocarbon fuel
21:
5128:
5127:
5123:
5122:
5121:
5119:
5118:
5117:
5083:
5082:
5081:
5076:
5060:
4977:
4952:
4900:
4834:
4803:
4757:
4731:Electromagnetic
4726:
4675:
4666:Pump-fed engine
4649:
4618:
4575:
4542:
4479:
4470:Rocket equation
4436:Reaction engine
4414:
4409:
4359:Wayback Machine
4348:
4343:
4342:
4332:
4330:
4317:
4316:
4312:
4302:
4300:
4285:
4281:
4271:Wayback Machine
4261:
4257:
4247:
4245:
4236:
4235:
4228:
4218:
4216:
4201:
4197:
4187:
4185:
4172:
4171:
4167:
4157:
4155:
4146:
4145:
4141:
4131:
4129:
4116:
4115:
4111:
4101:
4099:
4086:
4085:
4081:
4071:
4069:
4068:on 7 April 2004
4058:
4054:
4044:
4042:
4034:
4033:
4029:
4018:
4014:
4009:
4005:
4000:
3996:
3988:Hale, Francis,
3987:
3983:
3978:
3974:
3964:
3962:
3953:
3952:
3948:
3938:Wayback Machine
3928:
3924:
3914:
3912:
3911:on 28 June 2012
3908:
3897:
3891:
3887:
3877:
3875:
3864:
3860:
3850:
3848:
3840:
3839:
3835:
3825:
3823:
3813:
3809:
3799:
3797:
3791:"Nozzle Design"
3789:
3788:
3784:
3774:
3772:
3765:astronautix.com
3759:
3758:
3754:
3744:
3742:
3731:
3727:
3717:
3715:
3704:
3700:
3690:
3688:
3679:
3678:
3674:
3664:
3662:
3655:Popular Science
3649:
3648:
3644:
3634:
3632:
3623:
3622:
3618:
3591:
3587:
3574:
3573:
3569:
3559:
3557:
3553:
3546:
3542:
3541:
3537:
3527:
3525:
3512:
3511:
3507:
3497:
3495:
3482:
3481:
3474:
3469:on 13 May 2011.
3459:"Hyperion SSTO"
3457:
3456:
3452:
3435:
3434:
3430:
3415:"Pegasus VTOVL"
3413:
3412:
3408:
3403:on 28 May 2002.
3391:
3390:
3386:
3367:
3363:
3346:
3345:
3341:
3322:
3318:
3308:
3306:
3293:
3292:
3288:
3278:
3276:
3263:
3262:
3258:
3248:
3246:
3239:astronautix.com
3233:
3232:
3228:
3218:
3216:
3215:on 4 March 2016
3207:
3206:
3202:
3192:
3190:
3181:
3180:
3176:
3166:
3164:
3155:
3154:
3150:
3140:
3138:
3127:
3123:
3107:
3103:
3092:
3088:
3082:Wayback Machine
3068:
3064:
3052:
3046:
3042:
3032:
3030:
2987:
2983:
2978:
2974:
2964:
2962:
2961:on 15 June 2011
2958:
2947:
2941:
2932:
2927:
2905:
2903:Further reading
2900:
2806:
2736:mass production
2728:
2708:
2706:SpaceX Starship
2702:
2671:concept called
2658:
2652:
2642:and the Indian
2628:
2563:
2551:
2531:
2526:
2505:
2501:
2499:
2496:
2495:
2468:
2464:
2460:
2458:
2455:
2454:
2432:
2428:
2418:
2414:
2412:
2409:
2408:
2405:
2375:
2370:
2366:
2359:
2353:
2349:
2347:
2323:
2319:
2317:
2314:
2313:
2308:
2290:
2286:
2280:
2276:
2274:
2251:
2247:
2241:
2237:
2235:
2233:
2230:
2229:
2227:
2209:
2205:
2199:
2195:
2193:
2176:
2172:
2166:
2162:
2160:
2149:
2145:
2139:
2135:
2133:
2122:
2118:
2112:
2108:
2106:
2095:
2091:
2085:
2081:
2079:
2071:
2068:
2067:
2042:
2038:
2032:
2028:
2026:
2022:
2020:
2017:
2016:
2013:
1990:
1986:
1980:
1976:
1974:
1967:
1963:
1949:
1945:
1939:
1935:
1933:
1931:
1928:
1927:
1902:
1898:
1892:
1888:
1886:
1882:
1880:
1877:
1876:
1873:
1852:
1848:
1842:
1838:
1836:
1829:
1822:
1818:
1812:
1808:
1805:
1793:
1789:
1780:
1776:
1775:
1769:
1765:
1763:
1751:
1747:
1738:
1734:
1733:
1727:
1723:
1721:
1713:
1710:
1709:
1682:
1679:
1678:
1675:
1655:
1641:
1639:
1626:
1621:
1604:
1600:
1594:
1590:
1588:
1571:
1567:
1560:
1556:
1547:
1543:
1542:
1540:
1529:
1525:
1519:
1515:
1513:
1505:
1502:
1501:
1483:
1480:
1479:
1472:
1455:
1451:
1449:
1446:
1445:
1443:
1426:
1422:
1420:
1417:
1416:
1414:
1397:
1393:
1391:
1388:
1387:
1385:
1368:
1364:
1362:
1359:
1358:
1356:
1327:
1323:
1321:
1318:
1317:
1297:
1293:
1291:
1288:
1287:
1282:
1263:
1259:
1250:
1246:
1245:
1238:
1234:
1225:
1221:
1212:
1208:
1207:
1205:
1194:
1190:
1184:
1180:
1178:
1167:
1164:
1163:
1140:
1136:
1132:
1130:
1127:
1126:
1105:
1101:
1097:
1095:
1092:
1091:
1088:
1068:
1065:
1064:
1062:
1057:is the vehicle
1039:
1036:
1035:
1033:
1012:
1008:
1006:
1003:
1002:
1000:
979:
975:
973:
970:
969:
967:
944:
941:
940:
935:
901:
897:
888:
884:
873:
870:
869:
847:
838:
832:
819:nuclear thermal
811:
805:
784:space fountains
748:
653:
615:Flow separation
603:
592:
586:
583:
568:
552:
541:
461:
457:
456:
414:
345:nuclear-powered
337:
328:
322:
297:
291:
289:DC-X technology
160:
155:
92:low Earth orbit
28:
23:
22:
15:
12:
11:
5:
5126:
5116:
5115:
5110:
5108:Space vehicles
5105:
5100:
5095:
5078:
5077:
5065:
5062:
5061:
5059:
5058:
5057:
5056:
5051:
5041:
5036:
5031:
5026:
5021:
5016:
5011:
5006:
5001:
4999:Gravity assist
4996:
4991:
4985:
4983:
4979:
4978:
4976:
4975:
4970:
4964:
4962:
4961:External power
4958:
4957:
4954:
4953:
4951:
4950:
4949:
4948:
4938:
4937:
4936:
4934:Bussard ramjet
4926:
4921:
4920:
4919:
4908:
4906:
4902:
4901:
4899:
4898:
4893:
4892:
4891:
4886:
4881:
4876:
4866:
4861:
4855:
4853:
4846:
4840:
4839:
4836:
4835:
4833:
4832:
4827:
4822:
4817:
4811:
4809:
4805:
4804:
4802:
4801:
4796:
4791:
4786:
4781:
4776:
4771:
4765:
4763:
4762:Electrothermal
4759:
4758:
4756:
4755:
4750:
4745:
4740:
4734:
4732:
4728:
4727:
4725:
4724:
4723:
4722:
4717:
4712:
4702:
4696:
4694:
4687:
4681:
4680:
4677:
4676:
4674:
4673:
4668:
4663:
4657:
4655:
4651:
4650:
4648:
4647:
4642:
4637:
4635:Expander cycle
4632:
4626:
4624:
4620:
4619:
4617:
4616:
4611:
4606:
4604:Monopropellant
4601:
4600:
4599:
4594:
4583:
4581:
4577:
4576:
4574:
4573:
4568:
4563:
4557:
4555:
4548:
4544:
4543:
4541:
4540:
4535:
4530:
4525:
4520:
4515:
4514:
4513:
4503:
4498:
4493:
4487:
4485:
4481:
4480:
4478:
4477:
4475:Thermal rocket
4472:
4467:
4462:
4461:
4460:
4455:
4445:
4444:
4443:
4438:
4428:
4422:
4420:
4416:
4415:
4408:
4407:
4400:
4393:
4385:
4379:
4378:
4373:
4367:
4361:
4347:
4346:External links
4344:
4341:
4340:
4310:
4279:
4262:Thomson, Ian.
4255:
4226:
4195:
4165:
4139:
4128:on 2 June 2015
4109:
4079:
4062:"Shuttle SERV"
4052:
4027:
4012:
4003:
3994:
3981:
3972:
3946:
3922:
3885:
3858:
3833:
3807:
3782:
3771:on 2 July 2015
3752:
3725:
3698:
3672:
3642:
3616:
3585:
3567:
3535:
3505:
3472:
3450:
3428:
3406:
3384:
3361:
3339:
3316:
3286:
3256:
3226:
3200:
3174:
3148:
3121:
3101:
3086:
3062:
3040:
2981:
2972:
2929:
2928:
2926:
2923:
2922:
2921:
2904:
2901:
2899:
2898:
2893:
2888:
2883:
2878:
2873:
2871:Space elevator
2868:
2863:
2858:
2853:
2848:
2843:
2838:
2833:
2828:
2823:
2818:
2813:
2807:
2805:
2802:
2727:
2724:
2704:Main article:
2701:
2698:
2654:Main article:
2651:
2648:
2627:
2624:
2562:
2559:
2537:
2534:
2530:
2525:
2522:
2519:
2516:
2513:
2504:
2494:
2476:
2467:
2463:
2441:
2431:
2427:
2424:
2421:
2417:
2390:
2384:
2381:
2378:
2374:
2369:
2365:
2362:
2352:
2346:
2343:
2340:
2337:
2334:
2331:
2326:
2322:
2312:
2293:
2289:
2279:
2273:
2270:
2267:
2264:
2261:
2254:
2250:
2244:
2240:
2228:
2212:
2208:
2202:
2198:
2192:
2189:
2186:
2179:
2175:
2165:
2159:
2152:
2148:
2142:
2138:
2132:
2125:
2121:
2115:
2111:
2105:
2098:
2094:
2084:
2078:
2075:
2066:
2052:
2045:
2041:
2031:
2025:
2001:
1993:
1989:
1979:
1973:
1970:
1966:
1962:
1959:
1952:
1948:
1942:
1938:
1926:
1912:
1905:
1901:
1895:
1891:
1885:
1855:
1851:
1841:
1835:
1832:
1825:
1821:
1815:
1811:
1804:
1792:
1788:
1783:
1779:
1772:
1768:
1762:
1754:
1750:
1746:
1741:
1737:
1730:
1726:
1720:
1717:
1708:
1686:
1661:
1658:
1653:
1650:
1647:
1644:
1638:
1632:
1629:
1625:
1620:
1617:
1614:
1607:
1603:
1597:
1593:
1587:
1584:
1581:
1574:
1570:
1563:
1559:
1555:
1550:
1546:
1539:
1532:
1528:
1522:
1518:
1512:
1509:
1500:
1487:
1454:
1444:
1429:
1425:
1415:
1400:
1396:
1386:
1371:
1367:
1357:
1343:
1339:
1336:
1333:
1330:
1326:
1300:
1296:
1286:
1262:
1258:
1253:
1249:
1237:
1233:
1228:
1224:
1220:
1215:
1211:
1204:
1197:
1193:
1187:
1183:
1177:
1174:
1171:
1162:
1148:
1143:
1139:
1135:
1113:
1108:
1104:
1100:
1083:refers to the
1072:
1063:
1046:
1043:
1034:
1015:
1011:
1001:
978:
968:
951:
948:
939:
924:
921:
918:
915:
912:
909:
904:
900:
896:
887:
883:
880:
877:
868:
846:
843:
834:Main article:
831:
828:
807:Main article:
804:
801:
800:
799:
796:
787:
786:
777:
774:
769:
747:
746:Launch assists
744:
710:
709:
706:not dissimilar
699:
692:
689:
685:
682:
652:
649:
619:Rocketdyne J-2
605:
604:
555:
553:
546:
540:
537:
501:gravity losses
490:
489:
482:
479:
476:
473:
466:
449:
448:
445:
442:
439:
413:
410:
336:
333:
324:Main article:
321:
318:
293:Main article:
290:
287:
245:
244:
241:
238:Douglas SASSTO
235:
232:
229:
159:
158:Early concepts
156:
154:
151:
131:Apollo program
26:
9:
6:
4:
3:
2:
5125:
5114:
5111:
5109:
5106:
5104:
5101:
5099:
5096:
5094:
5091:
5090:
5088:
5075:
5074:
5069:
5063:
5055:
5052:
5050:
5047:
5046:
5045:
5042:
5040:
5037:
5035:
5032:
5030:
5027:
5025:
5022:
5020:
5017:
5015:
5012:
5010:
5009:Oberth effect
5007:
5005:
5002:
5000:
4997:
4995:
4992:
4990:
4987:
4986:
4984:
4980:
4974:
4971:
4969:
4966:
4965:
4963:
4959:
4947:
4944:
4943:
4942:
4939:
4935:
4932:
4931:
4930:
4929:Fusion rocket
4927:
4925:
4922:
4918:
4915:
4914:
4913:
4910:
4909:
4907:
4903:
4897:
4894:
4890:
4887:
4885:
4882:
4880:
4877:
4875:
4872:
4871:
4870:
4867:
4865:
4862:
4860:
4857:
4856:
4854:
4852:Closed system
4850:
4847:
4845:
4841:
4831:
4828:
4826:
4823:
4821:
4818:
4816:
4813:
4812:
4810:
4806:
4800:
4797:
4795:
4792:
4790:
4787:
4785:
4784:Arcjet rocket
4782:
4780:
4777:
4775:
4772:
4770:
4767:
4766:
4764:
4760:
4754:
4753:Plasma magnet
4751:
4749:
4746:
4744:
4741:
4739:
4736:
4735:
4733:
4729:
4721:
4718:
4716:
4713:
4711:
4708:
4707:
4706:
4703:
4701:
4698:
4697:
4695:
4693:Electrostatic
4691:
4688:
4686:
4682:
4672:
4669:
4667:
4664:
4662:
4659:
4658:
4656:
4652:
4646:
4645:Tap-off cycle
4643:
4641:
4638:
4636:
4633:
4631:
4628:
4627:
4625:
4621:
4615:
4614:Tripropellant
4612:
4610:
4607:
4605:
4602:
4598:
4595:
4593:
4590:
4589:
4588:
4585:
4584:
4582:
4578:
4572:
4569:
4567:
4564:
4562:
4559:
4558:
4556:
4552:
4549:
4545:
4539:
4536:
4534:
4533:Photon rocket
4531:
4529:
4526:
4524:
4523:Magnetic sail
4521:
4519:
4518:Electric sail
4516:
4512:
4509:
4508:
4507:
4504:
4502:
4499:
4497:
4494:
4492:
4489:
4488:
4486:
4482:
4476:
4473:
4471:
4468:
4466:
4463:
4459:
4456:
4454:
4451:
4450:
4449:
4446:
4442:
4441:Reaction mass
4439:
4437:
4434:
4433:
4432:
4431:Rocket engine
4429:
4427:
4424:
4423:
4421:
4417:
4413:
4406:
4401:
4399:
4394:
4392:
4387:
4386:
4383:
4377:
4374:
4371:
4368:
4365:
4362:
4360:
4356:
4353:
4350:
4349:
4328:
4324:
4320:
4314:
4298:
4294:
4290:
4283:
4276:
4272:
4268:
4265:
4259:
4243:
4239:
4233:
4231:
4214:
4210:
4206:
4199:
4183:
4179:
4175:
4169:
4153:
4149:
4143:
4127:
4123:
4119:
4113:
4097:
4093:
4089:
4083:
4067:
4063:
4056:
4041:
4037:
4031:
4024:
4023:
4016:
4007:
3998:
3991:
3985:
3976:
3960:
3956:
3950:
3943:
3939:
3935:
3932:
3926:
3907:
3903:
3896:
3889:
3873:
3869:
3862:
3847:
3843:
3837:
3822:
3818:
3811:
3796:
3792:
3786:
3770:
3766:
3762:
3756:
3740:
3736:
3729:
3713:
3709:
3702:
3686:
3682:
3676:
3660:
3656:
3652:
3646:
3630:
3626:
3620:
3612:
3608:
3604:
3600:
3596:
3589:
3581:
3577:
3571:
3552:
3545:
3539:
3523:
3519:
3515:
3509:
3493:
3489:
3485:
3479:
3477:
3468:
3464:
3460:
3454:
3446:
3442:
3438:
3432:
3424:
3420:
3416:
3410:
3402:
3398:
3394:
3388:
3380:
3376:
3372:
3365:
3357:
3353:
3349:
3343:
3335:
3331:
3327:
3320:
3304:
3300:
3296:
3290:
3274:
3270:
3266:
3260:
3244:
3240:
3236:
3230:
3214:
3210:
3204:
3188:
3184:
3178:
3162:
3158:
3152:
3136:
3132:
3125:
3119:
3118:0-7137-3504-X
3115:
3111:
3105:
3097:
3090:
3083:
3079:
3076:
3072:
3066:
3058:
3051:
3044:
3028:
3024:
3020:
3016:
3012:
3008:
3004:
3000:
2996:
2992:
2985:
2976:
2957:
2953:
2946:
2939:
2937:
2935:
2930:
2919:
2918:9780801873386
2915:
2911:
2907:
2906:
2897:
2894:
2892:
2889:
2887:
2884:
2882:
2879:
2877:
2874:
2872:
2869:
2867:
2864:
2862:
2859:
2857:
2856:Rockwell X-30
2854:
2852:
2849:
2847:
2844:
2842:
2841:Mass fraction
2839:
2837:
2834:
2832:
2829:
2827:
2824:
2822:
2819:
2817:
2814:
2812:
2809:
2808:
2801:
2799:
2795:
2791:
2787:
2783:
2779:
2775:
2774:Space Shuttle
2771:
2766:
2764:
2760:
2755:
2753:
2749:
2745:
2739:
2737:
2733:
2723:
2721:
2717:
2713:
2707:
2697:
2694:
2690:
2686:
2682:
2678:
2674:
2670:
2667:
2663:
2657:
2647:
2645:
2641:
2637:
2633:
2623:
2621:
2616:
2614:
2610:
2606:
2602:
2599:The uncrewed
2597:
2595:
2591:
2587:
2583:
2578:
2576:
2572:
2568:
2558:
2556:
2535:
2532:
2528:
2523:
2520:
2517:
2514:
2511:
2502:
2493:
2491:
2474:
2465:
2461:
2439:
2429:
2425:
2422:
2415:
2388:
2382:
2379:
2376:
2372:
2367:
2363:
2360:
2350:
2344:
2341:
2338:
2335:
2332:
2329:
2324:
2320:
2311:
2291:
2287:
2277:
2271:
2268:
2265:
2262:
2259:
2252:
2248:
2242:
2238:
2210:
2206:
2200:
2196:
2190:
2187:
2184:
2177:
2173:
2163:
2157:
2150:
2146:
2140:
2136:
2130:
2123:
2119:
2113:
2109:
2103:
2096:
2092:
2082:
2076:
2073:
2065:
2050:
2043:
2039:
2029:
2023:
1999:
1991:
1987:
1977:
1971:
1968:
1964:
1960:
1957:
1950:
1946:
1940:
1936:
1925:
1910:
1903:
1899:
1893:
1889:
1883:
1853:
1849:
1839:
1833:
1830:
1823:
1819:
1813:
1809:
1802:
1790:
1786:
1781:
1777:
1770:
1766:
1760:
1752:
1748:
1744:
1739:
1735:
1728:
1724:
1718:
1715:
1702:
1698:
1684:
1659:
1656:
1651:
1648:
1645:
1642:
1636:
1630:
1627:
1623:
1618:
1615:
1612:
1605:
1601:
1595:
1591:
1585:
1582:
1579:
1572:
1568:
1561:
1557:
1553:
1548:
1544:
1537:
1530:
1526:
1520:
1516:
1510:
1507:
1499:
1485:
1477:
1452:
1427:
1423:
1398:
1394:
1369:
1365:
1341:
1337:
1334:
1331:
1328:
1324:
1316:
1298:
1294:
1285:
1260:
1256:
1251:
1247:
1235:
1231:
1226:
1222:
1218:
1213:
1209:
1202:
1195:
1191:
1185:
1181:
1175:
1172:
1169:
1161:
1146:
1141:
1137:
1133:
1111:
1106:
1102:
1098:
1086:
1070:
1060:
1044:
1041:
1031:
1013:
1009:
998:
976:
965:
949:
938:
919:
916:
910:
907:
902:
898:
894:
885:
881:
878:
867:
865:
859:
854:
852:
842:
837:
827:
824:
820:
816:
815:Orion project
810:
797:
795:
792:
791:
790:
785:
781:
778:
775:
773:
770:
767:
763:
759:
756:
755:
754:
751:
743:
739:
737:
736:mass fraction
733:
729:
725:
720:
717:
715:
707:
703:
700:
697:
693:
690:
686:
683:
680:
676:
675:
674:
671:
669:
661:
657:
648:
644:
642:
638:
633:
631:
627:
622:
620:
616:
612:
601:
598:
590:
587:December 2017
580:
576:
572:
566:
565:
561:
556:This section
554:
550:
545:
544:
536:
533:
528:
526:
522:
519:In the 1960s
517:
515:
509:
507:
502:
497:
493:
487:
483:
480:
477:
474:
471:
467:
454:
453:
452:
446:
443:
440:
437:
436:
435:
432:
430:
426:
422:
418:
417:Hydrogen fuel
409:
407:
402:
398:
396:
392:
388:
384:
380:
375:
373:
369:
365:
361:
357:
352:
350:
346:
342:
332:
327:
326:Rotary Rocket
317:
314:
306:
301:
296:
286:
284:
281:tried to use
280:
276:
271:
269:
265:
261:
257:
253:
249:
242:
239:
236:
233:
230:
226:
225:
224:
221:
219:
218:hydrogen fuel
215:
211:
206:
203:
198:
196:
191:
187:
182:
180:
176:
171:
164:
150:
148:
144:
140:
136:
132:
128:
122:
120:
116:
112:
108:
104:
99:
97:
93:
88:
86:
81:
76:
72:
70:
67:
63:
59:
55:
51:
43:
39:
34:
30:
19:
5103:Space access
5071:
5014:Space launch
4946:Fission sail
4874:Radioisotope
4705:Ion thruster
4623:Power cycles
4609:Bipropellant
4501:Steam rocket
4496:Water rocket
4331:. Retrieved
4327:the original
4322:
4313:
4301:. Retrieved
4292:
4282:
4275:The Register
4274:
4258:
4246:. Retrieved
4217:. Retrieved
4213:the original
4208:
4198:
4186:. Retrieved
4177:
4168:
4156:. Retrieved
4152:the original
4142:
4130:. Retrieved
4126:the original
4121:
4112:
4100:. Retrieved
4091:
4082:
4070:. Retrieved
4066:the original
4055:
4043:. Retrieved
4039:
4030:
4020:
4015:
4006:
3997:
3989:
3984:
3975:
3963:. Retrieved
3949:
3941:
3925:
3913:. Retrieved
3906:the original
3888:
3876:. Retrieved
3872:the original
3861:
3849:. Retrieved
3845:
3836:
3824:. Retrieved
3820:
3810:
3798:. Retrieved
3794:
3785:
3773:. Retrieved
3769:the original
3764:
3755:
3743:. Retrieved
3728:
3718:14 September
3716:. Retrieved
3701:
3691:14 September
3689:. Retrieved
3675:
3663:. Retrieved
3654:
3645:
3633:. Retrieved
3628:
3619:
3611:the original
3598:
3588:
3580:the original
3570:
3558:. Retrieved
3538:
3526:. Retrieved
3518:www.vice.com
3517:
3508:
3496:. Retrieved
3492:the original
3487:
3484:"Star-raker"
3467:the original
3462:
3453:
3445:the original
3440:
3431:
3423:the original
3418:
3409:
3401:the original
3396:
3387:
3379:the original
3374:
3364:
3356:the original
3351:
3342:
3334:the original
3329:
3319:
3307:. Retrieved
3298:
3289:
3277:. Retrieved
3268:
3259:
3247:. Retrieved
3243:the original
3238:
3229:
3217:. Retrieved
3213:the original
3203:
3191:. Retrieved
3177:
3165:. Retrieved
3151:
3139:. Retrieved
3135:the original
3129:Wade, Mark.
3124:
3109:
3104:
3095:
3089:
3065:
3056:
3043:
3033:24 September
3031:. Retrieved
2998:
2994:
2984:
2975:
2963:. Retrieved
2956:the original
2909:
2851:Orbital ring
2786:Falcon Heavy
2767:
2756:
2752:OTRAG rocket
2744:West Germany
2740:
2729:
2709:
2693:Sabre engine
2659:
2646:spaceplane.
2636:ARCA Haas 2C
2629:
2617:
2598:
2586:Shuttle SERV
2579:
2564:
2552:
2406:
2309:
2014:
1874:
1676:
1473:
1283:
1089:
936:
861:
856:
851:Robert Truax
848:
839:
812:
794:Space tether
788:
752:
749:
740:
721:
718:
711:
672:
665:
645:
634:
623:
608:
593:
584:
569:Please help
557:
529:
518:
510:
498:
494:
491:
484:Has a large
450:
433:
415:
403:
399:
386:
376:
353:
338:
329:
309:
272:
259:
247:
246:
222:
207:
199:
183:
172:
169:
139:Luna program
135:Lunar Module
123:
100:
89:
77:
73:
53:
49:
47:
29:
5029:Aerocapture
5024:Aerobraking
4905:Open system
4889:"Lightbulb"
4830:Mass driver
4580:Propellants
4511:Diffractive
4333:20 November
4248:28 November
4219:28 February
3965:25 November
3915:15 November
3878:15 November
3745:15 November
3001:: 415β421.
2891:VentureStar
2831:Launch loop
2826:Kankoh-maru
2794:Blue Origin
2780:with their
2720:heat shield
2632:Kankoh-maru
2590:jet engines
758:sled launch
521:Philip Bono
372:Quicklaunch
358:to achieve
175:Philip Bono
115:VentureStar
38:VentureStar
5087:Categories
5049:Warp drive
4879:Salt-water
4597:Hypergolic
4506:Solar sail
4303:8 December
4045:8 December
3851:8 December
3826:8 December
3800:8 December
3631:. May 1996
3269:pmview.com
3219:18 October
3193:18 October
3167:18 October
3141:18 October
2925:References
2765:still do.
2669:spaceplane
2640:Radian One
1059:mass ratio
662:spaceplane
395:hypersonic
391:supersonic
356:propellant
349:jet-engine
335:Approaches
260:Star-Raker
250:: In 1979
248:Star-raker
210:spaceplane
119:Roton SSTO
66:expendable
42:spaceplane
4592:Cryogenic
3944:, 07/1985
3629:wired.com
3607:0015-3710
3560:15 August
3528:15 August
3498:15 August
3393:"Ithacus"
3023:0094-5765
2846:NASA X-43
2798:New Glenn
2746:with the
2681:Alan Bond
2634:project,
2615:to NASA.
2521:ζ
2518:−
2503:λ
2420:Δ
2383:λ
2380:−
2373:ζ
2364:−
2272:−
2269:ζ
2266:−
2188:ζ
1972:−
1961:λ
1834:−
1787:−
1716:λ
1685:λ
1649:−
1619:−
1586:−
1554:−
1508:ζ
1486:ζ
1087:function.
947:Δ
911:
895:⋅
876:Δ
817:and some
679:scramjets
558:does not
470:cryogenic
374:project.
368:space gun
147:Chang'e 6
143:Chang'e 5
4884:Gas core
4419:Concepts
4355:Archived
4297:Archived
4267:Archived
4242:Archived
4182:Archived
4096:Archived
3959:Archived
3934:Archived
3739:Archived
3712:Archived
3685:Archived
3659:Archived
3551:Archived
3522:Archived
3437:"SASSTO"
3348:"Rombus"
3303:Archived
3299:nasa.gov
3273:Archived
3187:Archived
3161:Archived
3078:Archived
3027:Archived
2866:Scramjet
2804:See also
2790:Starship
2782:Falcon 9
2770:reusable
2700:Starship
2607:for the
2561:Examples
766:StarTram
632:design.
429:kerosene
406:Titan II
341:scramjet
4973:Tethers
4825:MagBeam
4710:Gridded
4465:Staging
4458:Delta-v
4319:"Otrag"
4293:Twitter
4188:13 June
4158:1 March
4132:13 June
4102:13 June
4072:1 April
3775:13 June
3761:"VTOVL"
3635:13 June
3309:13 June
3279:13 June
3249:13 June
3073:(PDF).
3003:Bibcode
2965:5 March
2759:Russian
2750:-based
1284:where:
1028:is the
964:delta-v
937:where:
768:, etc.)
579:removed
564:sources
514:propane
512:liquid
506:delta-v
468:Deeply
460:⁄
381:costs,
364:payload
153:History
129:by the
94:or the
4799:VASIMR
4448:Thrust
4426:Rocket
3868:"X-30"
3665:15 May
3605:
3576:"X-30"
3131:"OOST"
3116:
3021:
2916:
2796:using
2792:, and
2788:, and
2683:after
2673:Skylon
2650:Skylon
2644:Avatar
2573:. The
764:, and
660:Skylon
611:nozzle
421:oxygen
228:close.
109:, the
103:Skylon
4808:Other
4554:State
3909:(PDF)
3898:(PDF)
3554:(PDF)
3547:(PDF)
3053:(PDF)
2959:(PDF)
2948:(PDF)
2861:Roton
2685:HOTOL
732:ATREX
730:(and
360:orbit
320:Roton
279:HOTOL
186:NEXUS
58:orbit
4538:WINE
4335:2019
4305:2021
4250:2012
4221:2011
4190:2015
4160:2011
4134:2015
4104:2015
4074:2010
4047:2021
3967:2018
3917:2007
3880:2007
3853:2021
3828:2021
3821:NASA
3802:2021
3777:2015
3747:2007
3720:2009
3693:2009
3667:2021
3637:2015
3603:ISSN
3562:2020
3530:2020
3500:2020
3375:AIAA
3330:AIAA
3311:2015
3281:2015
3251:2015
3221:2015
3195:2015
3169:2015
3143:2015
3114:ISBN
3075:ICES
3059:: 1.
3035:2021
3019:ISSN
2967:2011
2952:JBIS
2914:ISBN
2761:and
2618:The
2601:DC-X
2594:USAF
2571:Mars
2567:Moon
1705:Isp.
1474:The
862:The
798:tugs
714:X-43
630:X-33
562:any
560:cite
532:DC-X
313:NASA
305:DC-X
275:NASP
268:SSME
200:The
195:Mars
145:and
127:Moon
113:and
107:DC-X
54:SSTO
36:The
18:SSTO
3011:doi
2662:ESA
2569:or
2507:max
696:Isp
573:by
393:or
387:and
133:'s
5089::
4321:.
4295:.
4291:.
4273:.
4229:^
4207:.
4180:.
4176:.
4120:.
4090:.
4038:.
3957:.
3940:,
3900:.
3844:.
3819:.
3793:.
3763:.
3737:.
3710:.
3683:.
3653:.
3627:.
3597:,
3549:.
3520:.
3516:.
3486:.
3475:^
3461:.
3439:.
3417:.
3395:.
3373:.
3350:.
3328:.
3301:.
3297:.
3271:.
3267:.
3237:.
3112:,
3055:.
3025:.
3017:.
3009:.
2999:30
2997:.
2993:.
2950:.
2933:^
2800:.
2784:,
2754:.
2638:,
2470:sp
2434:pl
2355:pl
2282:pl
2168:pl
2087:pl
2034:pl
1982:pl
1844:pl
1795:pl
1457:pl
1265:pl
1240:pl
1071:ln
981:sp
908:ln
890:sp
853::
643:.
431:.
197:.
71:.
48:A
4404:e
4397:t
4390:v
4337:.
4307:.
4252:.
4223:.
4192:.
4162:.
4136:.
4106:.
4076:.
4049:.
3969:.
3919:.
3882:.
3855:.
3830:.
3804:.
3779:.
3749:.
3722:.
3695:.
3669:.
3639:.
3564:.
3532:.
3502:.
3313:.
3283:.
3253:.
3223:.
3197:.
3171:.
3145:.
3037:.
3013::
3005::
2969:.
2920:.
2536:R
2533:M
2529:1
2524:=
2515:1
2512:=
2475:)
2466:I
2462:(
2440:)
2430:m
2426:,
2423:v
2416:(
2389:)
2377:1
2368:(
2361:1
2351:m
2345:=
2342:W
2339:O
2336:L
2333:G
2330:=
2325:i
2321:m
2292:i
2288:m
2278:m
2263:1
2260:=
2253:i
2249:m
2243:s
2239:m
2211:i
2207:m
2201:s
2197:m
2191:+
2185:+
2178:i
2174:m
2164:m
2158:=
2151:i
2147:m
2141:s
2137:m
2131:+
2124:i
2120:m
2114:p
2110:m
2104:+
2097:i
2093:m
2083:m
2077:=
2074:1
2051:)
2044:i
2040:m
2030:m
2024:(
2000:)
1992:i
1988:m
1978:m
1969:1
1965:(
1958:=
1951:i
1947:m
1941:s
1937:m
1911:)
1904:i
1900:m
1894:s
1890:m
1884:(
1854:i
1850:m
1840:m
1831:1
1824:i
1820:m
1814:s
1810:m
1803:=
1791:m
1782:i
1778:m
1771:s
1767:m
1761:=
1753:s
1749:m
1745:+
1740:p
1736:m
1729:s
1725:m
1719:=
1660:R
1657:M
1652:1
1646:R
1643:M
1637:=
1631:R
1628:M
1624:1
1616:1
1613:=
1606:i
1602:m
1596:f
1592:m
1583:1
1580:=
1573:i
1569:m
1562:f
1558:m
1549:i
1545:m
1538:=
1531:i
1527:m
1521:p
1517:m
1511:=
1478:(
1453:m
1428:p
1424:m
1399:s
1395:m
1370:f
1366:m
1355:,
1342:)
1338:W
1335:O
1332:L
1329:G
1325:(
1299:i
1295:m
1261:m
1257:+
1252:s
1248:m
1236:m
1232:+
1227:s
1223:m
1219:+
1214:p
1210:m
1203:=
1196:f
1192:m
1186:i
1182:m
1176:=
1173:R
1170:M
1147:)
1142:f
1138:m
1134:(
1112:)
1107:i
1103:m
1099:(
1061:,
1045:R
1042:M
1032:,
1014:0
1010:g
999:,
977:I
962:(
950:v
923:)
920:R
917:M
914:(
903:0
899:g
886:I
882:=
879:v
782:/
708:.
600:)
594:(
589:)
585:(
581:.
567:.
462:7
458:1
52:(
44:.
20:)
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