Aerobraking
Aerobraking is a
Method
When an interplanetary vehicle arrives at its destination, it must reduce its velocity to achieve orbit or to land. To reach a low, near-circular orbit around a body with substantial gravity (as is required for many scientific studies), the required velocity changes can be on the order of kilometers per second. Using propulsion, the rocket equation dictates that a large fraction of the spacecraft mass must consist of fuel. This reduces the science payload and/or requires a large and expensive rocket. Provided the target body has an atmosphere, aerobraking can be used to reduce fuel requirements. The use of a relatively small burn allows the spacecraft to enter an elongated elliptic orbit. Aerobraking then shortens the orbit into a circle. If the atmosphere is thick enough, a single pass can be sufficient to adjust the orbit. However, aerobraking typically requires multiple orbits higher in the atmosphere. This reduces the effects of frictional heating, unpredictable turbulence effects, atmospheric composition, and temperature.
Aerobraking done this way allows sufficient time after each pass to measure the velocity change and make corrections for the next pass. Achieving the final orbit may take over six
The kinetic energy
Regarding spacecraft navigation,
Many spacecraft use solar panels to power their operations. The panels can be used to refine aerobraking to reduce the number of required orbits. The panels rotate according to an AI-powered algorithm to increase/reduce drag and can reduce arrival times from months to weeks.[6]
Related methods
Aerocapture is a related but more extreme method in which no initial orbit-injection burn is performed. Instead, the spacecraft plunges deeply into the atmosphere without an initial insertion burn, and emerges from this single pass in the atmosphere with an apoapsis near that of the desired orbit. Several small correction burns are then used to raise the periapsis and perform final adjustments.[7]
This method was originally planned for the
Another related technique is that of aerogravity assist, in which the spacecraft flies through the upper atmosphere and uses aerodynamic lift instead of drag at the point of closest approach. If correctly oriented, this can increase the deflection angle above that of a pure gravity assist, resulting in a larger delta-v.[9]
Spacecraft missions
Although the theory of aerobraking is well developed, using the technique is difficult because a very detailed knowledge of the character of the target planet's atmosphere is needed in order to plan the maneuver correctly. Currently, the deceleration is monitored during each maneuver and plans are modified accordingly. Since no spacecraft can yet aerobrake safely on its own, this requires constant attention from both human controllers and the
On 19 March 1991, aerobraking was demonstrated by the Hiten spacecraft. This was the first aerobraking maneuver by a deep space probe.[11] Hiten (a.k.a. MUSES-A) was launched by the Institute of Space and Astronautical Science (ISAS) of Japan.[12] Hiten flew by the Earth at an altitude of 125.5 km over the Pacific at 11.0 km/s. Atmospheric drag lowered the velocity by 1.712 m/s and the apogee altitude by 8665 km.[13] Another aerobraking maneuver was conducted on 30 March.
In May 1993, aerobraking was used during the extended
In 1997, the
In 2014, an aerobraking experiment was successfully performed on a test basis near the end of the mission of the ESA probe Venus Express.[16][17]
In 2017–2018, the ESA ExoMars Trace Gas Orbiter performed aerobraking at Mars to reduce the apocentre of the orbit, being the first operational aerobraking for a European mission.[18]
Aerobraking in fiction
In Robert A. Heinlein's 1948 novel Space Cadet, aerobraking is used to save fuel while slowing the spacecraft Aes Triplex for an unplanned extended mission and landing on Venus, during a transit from the Asteroid Belt to Earth.[20]
The spacecraft Cosmonaut Alexei Leonov in
In the 2004 TV series
In the
In the space simulation sandbox game Kerbal Space Program, this is a common method of reducing a craft's orbital speed. It is sometimes humorously referred to as "aerobreaking", because the high drag sometimes causes large crafts to split in several parts.
In Kim Stanley Robinson's Mars trilogy, the Ares spaceship carrying the first hundred humans to arrive on Mars uses aerobraking to enter into orbit around the planet. Later in the books, as an effort to thicken the atmosphere, scientists bring an asteroid into aerobraking in order to vaporize it and release its contents into the atmosphere.
In the 2014 film Interstellar, astronaut pilot Cooper uses aerobraking to save fuel and slow the spacecraft Ranger upon exiting the wormhole to arrive in orbit above the first planet.
Aerodynamic braking
Aerodynamic braking is a method used in landing aircraft to assist the wheel brakes in stopping the plane. It is often used for short runway landings or when conditions are wet, icy or slippery. Aerodynamic braking is performed immediately after the rear wheels (main mounts) touch down, but before the nose wheel drops. The pilot begins to pull back on the stick, applying elevator pressure to hold the nose high. The nose-high attitude exposes more of the craft's surface-area to the flow of air, which produces greater drag, helping to slow the plane. The raised elevators also cause air to push down on the rear of the craft, forcing the rear wheels harder against the ground, which aids the wheel brakes by helping to prevent skidding. The pilot will usually continue to hold back on the stick even after the elevators lose their authority, and the nose wheel drops, to keep added pressure on the rear wheels.
Aerodynamic braking is a common braking technique during landing, which can also help to protect the wheel brakes and tires from excess wear, or from locking up and sending the craft sliding out of control. It is often used by private pilots, commercial planes, fighter aircraft, and was used by the Space Shuttles during landings.[21][22][23]
-
An F-22 Raptor landing atElmendorf AFB, demonstrating aerodynamic braking.
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Aerodynamic braking in Space Shuttle landings.
See also
- Aerocapture
- Boost-glide
- Lithobraking
References
- ^ Jill L. Hanna Prince & Scott A. Striepe. "NASA LANGLEY TRAJECTORY SIMULATION AND ANALYSIS CAPABILITIES FOR MARS RECONNAISSANCE ORBITER" (PDF). NASA Langley Research Center. Archived from the original (PDF) on 2009-03-20. Retrieved 2008-06-09.
- ^ "Aerobreaking". www.spacedaily.com.
- ^ "Spaceflight Now | Destination Mars | Spacecraft enters orbit around Mars". spaceflightnow.com.
- doi:10.2514/1.24304.
- ^ Moriba K. Jah. "Inertial Measurements for Aero-Assisted Navigation NPO-43677". Tech Briefs. Retrieved 2020-08-02.
- ^ Strickler, Jordan (2022-01-20). "New AI improves orbit entry for Mars satellites". ZME Science. Retrieved 2022-02-04.
- ^ a b Percy, T.K.; Bright, E. & Torres, A.O. (2005). "Assessing the Relative Risk of Aerocapture Using Probabilistic Risk Assessment" (PDF).
- ^ "SCIENCE TEAM AND INSTRUMENTS SELECTED FOR MARS SURVEYOR 2001 MISSIONS". 6 November 1997.
- ^ McRonald, Angus D.; Randolph, James E. (Jan 8–11, 1990). "Hypersonic maneuvering to provide planetary gravity assist". AIAA-1990-539, 28th Aerospace Sciences Meeting. Reno, NV.
- ^ Prince, Jill L. H.; Powell, Richard W.; Murri, Dan. "Autonomous Aerobraking: A Design, Development, and Feasibility Study" (PDF). NASA Langley Research Center. NASA Technical Reports Server. Retrieved 15 September 2011.
- ^ "Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958–2000" Archived 2008-09-25 at the Wayback Machine by Asif A. Siddiqi, NASA Monographs in Aerospace History No. 24.
- ^ J. Kawaguchi, T. Icbikawa, T. Nishimura, K. Uesugi, L. Efron, J. Ellis, P. R. Menon and B. Tucker, "Navigation for Muses-A (HITEN) Aerobraking in the Earth's Atmosphere – Preliminary Report" Archived December 26, 2010, at the Wayback Machine, Proceedings of the 47th Annual Meeting of the Institute of Navigation June 10–12, 1991, pp.17–27.
- ^ "Muses A (Hiten)". Gunter's Space Page.
- ISSN 0094-5765.
- ^ "Magellan Begins Windmill Experiment". www2.jpl.nasa.gov.
- ^ "Surfing an alien atmosphere". ESA.int. European Space Agency. Retrieved 11 June 2015.
- ^ "Venus Express rises again". ESA.int. European Space Agency. Retrieved 11 June 2015.
- ^ "ESA - Robotic Exploration of Mars - Surfing complete". exploration.esa.int.
- from the original on 13 October 2023. Retrieved 1 May 2017.
- ISBN 978-1-4299-1253-2.
- ^ Airplane Flying Handbook By the Federal Aviation Administration – Skyhorse Publishing 2007
- ^ "Publications". Archived from the original on 2016-06-10. Retrieved 2012-07-31.
- ^ Cosmic Perspectives in Space Physics By S. Biswas – Kluwer Academic Publishing 2000 Page 28
Further reading
- JPL aerobraking report for MGS
- An Explanation of How Aerobraking Works (PDF)
- Hoffman, S. (August 20–22, 1984). A comparison of aerobraking and aerocapture vehicles for interplanetary missions. AIAA and AAS, Astrodynamics Conference. Seattle, Washington: American Institute of Aeronautics and Astronautics. pp. 25 p.. Retrieved 2007-07-31.