DSE-Alpha
Encyclopedia
Deep Space Expedition Alpha (DSE-Alpha), is the name given to the mission
proposed in 2005 to take the first space tourists
to fly around the Moon
. The mission is organized by Space Adventures Ltd.
, a commercial spaceflight company. The plans involve a modified Soyuz capsule docking with a booster rocket in Earth orbit which then sends the spacecraft on a free return circumlunar trajectory
that circles around the Moon once. While the price was originally announced in August 2005 to cost US$100 million per seat, Space Adventures founder Eric Anderson
announced in January 2011 that one of the two available seats had been sold for $150 million. Launch is targeted for 2015.
, made several attempts at circumlunar flight, with eventual success.
The DSE proposal is to launch the Soyuz with one crew member and two passengers aboard; a Zenit rocket booster will then be launched carrying a rocket stage weighing up to 14.5t, to dock with the Soyuz and propel it to circumlunar velocity. Two different flight profiles were originally proposed by Space Adventures. The direct-staged profile, lasting about 8-9 days, would involve docking to the booster stage intended to propel the craft and direct departure for the Moon. A proposed timeline for such a flight plan is as follows:
The other profile, lasting about 9-21 days, would incorporate a several day visit to the International Space Station
into the flight plan before rendezvousing with the booster stage and departing for the Moon.
The Soyuz spacecraft used for the mission would be modified from the orbital Soyuz
, with a thicker and more durable heat shield
and a Yamal satellite
communications system. The Block DM booster would use an automatic docking system for the rendezvous with the Soyuz in low-earth orbit.
On June 28, 2007 Space.com
reported that two individuals had displayed interest in purchasing seats with contract negotiations expected to be concluded by the end of the year. In January 2011, Space Adventures founder Eric Anderson announced that one of the two seats on the flight had been sold at a price of US$150 million, and negotiations for the second seat were under way, with the flight targeted for a 2015 launch.
, has argued, however, that the Zenit rocket is not powerful enough for this mission and that the larger Proton rocket will in fact be needed. These same calculations have also shown that a fully fueled and outfitted Block DM would be beyond the capabilities of the Zenit rocket, and the DM would have to fire for a short time in order to stabilize its orbit.
Another criticism that has been levied is that the unmanned Zond missions were only partially successful, with one spacecraft suffering cabin depressurisation, and all but one failing to follow the correct re-entry and landing trajectory. If the trajectory problem were to recur on a manned mission the crew would be at risk of potentially dangerous g-forces
and a sea landing in a remote area.
Lunar sortie
A lunar sortie is a human spaceflight mission to the Moon. In contrast with lunar outpost missions, lunar sorties will be of relatively brief duration.- NASA sorties :...
proposed in 2005 to take the first space tourists
Space tourism
Space Tourism is space travel for recreational, leisure or business purposes. A number of startup companies have sprung up in recent years, hoping to create a space tourism industry...
to fly around the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
. The mission is organized by Space Adventures Ltd.
Space Adventures
Space Adventures, Ltd. is a Virginia, USA-based space tourism company founded in 1998 by Eric C. Anderson. , offerings include zero-gravity atmospheric flights, orbital spaceflights , and other spaceflight-related experiences including cosmonaut training, spacewalk training, and launch tours...
, a commercial spaceflight company. The plans involve a modified Soyuz capsule docking with a booster rocket in Earth orbit which then sends the spacecraft on a free return circumlunar trajectory
Circumlunar trajectory
A Circumlunar trajectory, Trans-Lunar trajectory or Lunar free return is a type of free return trajectory which takes a spacecraft from Earth, around the far side of the Moon, and back to Earth.-Background:...
that circles around the Moon once. While the price was originally announced in August 2005 to cost US$100 million per seat, Space Adventures founder Eric Anderson
Eric C. Anderson
Eric Anderson is an entrepreneur and aerospace engineer known for co-founding Space Adventures, a commercial spaceflight company that brokers spaceflight experiences.-Early life and education:...
announced in January 2011 that one of the two available seats had been sold for $150 million. Launch is targeted for 2015.
Concept
The use of the Soyuz spacecraft makes sense in many ways; the original Soyuz design of 1962 was specifically intended for circumlunar travel. In the late 1960s a stripped down Soyuz variant, under the name ZondZond program
Zond was the name given to two distinct series of Soviet unmanned space program undertaken from 1964 to 1970. The first series based on 3MV planetary probe was intended to gather information about nearby planets...
, made several attempts at circumlunar flight, with eventual success.
The DSE proposal is to launch the Soyuz with one crew member and two passengers aboard; a Zenit rocket booster will then be launched carrying a rocket stage weighing up to 14.5t, to dock with the Soyuz and propel it to circumlunar velocity. Two different flight profiles were originally proposed by Space Adventures. The direct-staged profile, lasting about 8-9 days, would involve docking to the booster stage intended to propel the craft and direct departure for the Moon. A proposed timeline for such a flight plan is as follows:
- Day 1: Launch of Soyuz spacecraft into low-earth orbit
- Day 2: Launch of Block DM upper stage on rocket booster
- Day 3: RendezvousSpace rendezvousA space rendezvous is an orbital maneuver during which two spacecraft, one of which is often a space station, arrive at the same orbit and approach to a very close distance . Rendezvous requires a precise match of the orbital velocities of the two spacecraft, allowing them to remain at a constant...
and docking of Soyuz with booster, trans-lunar injection burn after checkout of systems - Days 4-5: Coast to the Moon on circumlunar trajectoryCircumlunar trajectoryA Circumlunar trajectory, Trans-Lunar trajectory or Lunar free return is a type of free return trajectory which takes a spacecraft from Earth, around the far side of the Moon, and back to Earth.-Background:...
- Day 6: Closest approach as the Soyuz loops around the far side of the MoonFar side of the MoonThe far side of the Moon is the lunar hemisphere that is permanently turned away, and is not visible from the surface of the Earth. The far hemisphere was first photographed by the Soviet Luna 3 probe in 1959, and was first directly observed by human eyes when the Apollo 8 mission orbited the Moon...
- Days 7-8: Coast back to Earth
- Day 9: Atmospheric reentryAtmospheric reentryAtmospheric entry is the movement of human-made or natural objects as they enter the atmosphere of a celestial body from outer space—in the case of Earth from an altitude above the Kármán Line,...
and landing
The other profile, lasting about 9-21 days, would incorporate a several day visit to the International Space Station
International Space Station
The International Space Station is a habitable, artificial satellite in low Earth orbit. The ISS follows the Salyut, Almaz, Cosmos, Skylab, and Mir space stations, as the 11th space station launched, not including the Genesis I and II prototypes...
into the flight plan before rendezvousing with the booster stage and departing for the Moon.
The Soyuz spacecraft used for the mission would be modified from the orbital Soyuz
Soyuz-TMA
The Soyuz-TMA is a recent revision of the Soyuz spacecraft, superseded in 2010 by the Soyuz TMA-M..It is used by the Russian Federal Space Agency for human spaceflight...
, with a thicker and more durable heat shield
Heat shield
A heat shield is designed to shield a substance from absorbing excessive heat from an outside source by either dissipating, reflecting or simply absorbing the heat...
and a Yamal satellite
Yamal (satellite)
Yamal is a communication satellite developed by Gazprom Space Systems for Russian Direct-To-Home television. The first satellite of the Yamal series was launched by September 6, 1999.-External links:**...
communications system. The Block DM booster would use an automatic docking system for the rendezvous with the Soyuz in low-earth orbit.
On June 28, 2007 Space.com
Space.com
Space.com is a space and astronomy news website. Its stories are often syndicated to other media outlets, including CNN, MSNBC, Yahoo!, and USA Today.Space.com was founded by former CNN anchor Lou Dobbs and Rich Zahradnik, in July 1999...
reported that two individuals had displayed interest in purchasing seats with contract negotiations expected to be concluded by the end of the year. In January 2011, Space Adventures founder Eric Anderson announced that one of the two seats on the flight had been sold at a price of US$150 million, and negotiations for the second seat were under way, with the flight targeted for a 2015 launch.
Criticism
Mark Wade, author of the Encyclopedia AstronauticaEncyclopedia Astronautica
The Encyclopedia Astronautica is a reference web site on space travel. A comprehensive catalog of vehicles, technology, astronauts, and flights, it includes information from most countries that have had an active rocket research program, from Robert Goddard to the NASA Space shuttle to the Soviet...
, has argued, however, that the Zenit rocket is not powerful enough for this mission and that the larger Proton rocket will in fact be needed. These same calculations have also shown that a fully fueled and outfitted Block DM would be beyond the capabilities of the Zenit rocket, and the DM would have to fire for a short time in order to stabilize its orbit.
Another criticism that has been levied is that the unmanned Zond missions were only partially successful, with one spacecraft suffering cabin depressurisation, and all but one failing to follow the correct re-entry and landing trajectory. If the trajectory problem were to recur on a manned mission the crew would be at risk of potentially dangerous g-forces
G-force
The g-force associated with an object is its acceleration relative to free-fall. This acceleration experienced by an object is due to the vector sum of non-gravitational forces acting on an object free to move. The accelerations that are not produced by gravity are termed proper accelerations, and...
and a sea landing in a remote area.