Russian engineers are planning to upgrade the country's crew-carrying Soyuz capsule to bring spaceflyers on a trip around the moon.
Space tourism firm Space Adventures says two customers have paid deposits for a flight around the moon on a Soyuz spacecraft, but the trip requires major changes to the Russian crew capsule, a vehicle that has seen only incremental upgrades in recent decades.
While the Virginia-based company works with Russian engineers to make the venerable Soyuz ferry craft ready for a lunar voyage, Space Adventures president Tom Shelley said last week he expects prices for tourist trips to the International Space Station to fall once U.S.-built capsules begin flying astronauts into low Earth orbit.
The flight around the moon goes for $150 million per person, and a seat on a Soyuz mission to the space station is priced at $52 million, according to Shelley. [Russia's Manned Soyuz Space Capsule Explained (Infographic)]
Seven space tourists have flown to the space station on flights arranged by Space Adventures. British opera singer Sarah Brightman has reserved a 10-day spaceflight to the space station for late 2015 and is set to begin training in early 2015.
The lunar mission would carry a crew commanded by a professional Russian cosmonaut. Two paying passengers would make for a $300 million mission.
"When you put in perspective of the Apollo program and the cost of access to space in general, it's actually very affordable," Shelley said. "Well, it's good value. Let's put it that way. Maybe affordable is the wrong choice of word."
Speaking to the National Space Club Florida Committee on June 10, Shelley said Soyuz contractor Energia plans to modify the spacecraft for the moon mission by changing the ship's communications and navigation systems.
"We are going to have to change the heat shield because you're re-entering at a significantly higher speed" on a lunar mission, Shelley said, adding engineers are considering whether to guide the Soyuz landing capsule to a "skip re-entry" in which the spacecraft would dip into the atmosphere to dissipate speed before plunging to the surface to a parachute-assisted touchdown.
The Soviet-era Zond robotic circumlunar missions, intended to pave the way for future human voyages, pioneered the skip re-entry technique in the 1960s.
The Soyuz also needs a new habitation module to give the crew more living space during the week-long trip from Earth to the moon and back.
"We're basically taking the same Soyuz that flies to the space station, making a few modifications to allow it go around the far aside of the moon, and adding an extra habitation module to make it more comfortable for the passengers," Shelley said.
The probable flight plan calls for the moon-bound crew to fly to the space station on a Soyuz rocket and spacecraft for a few days, then undock and rendezvous with a habitation module and Block DM propulsion stage launched separately atop a Proton booster.
The Block DM engine would propel the Soyuz capsule on a trajectory once around the far side of the moon and back to Earth.
If the flight includes a visit to the space station, the mission's total duration will be about 17 days, according to Shelley.
An unmanned lunar flight is planned before Russian launches a piloted mission, Shelley said, and the earliest opportunity for a tourist trip is late 2017. [Read more from Spaceflight Now]
"We are exploring all possible avenues of cooperation with them, and we can do this -- circle the moon in 2017 to 2018 on Soyuz. Technically it is possible," said Vitaly Lopota, CEO of Energia, in a report by Russia's Interfax news agency.
Early concepts for the Soyuz spacecraft from the 1960s included variants designed for lunar missions, but Russia never sent cosmonauts to the moon.
"That would be a very aggressive schedule," Shelley told reporters June 13. "I think late 2017 or 2018 is feasible, but that's what we're figuring out at the moment -- going through all the various different design changes to meet our customer requirements and technical requirements to actually complete the mission. That's what we're doing with the Russians at the moment, and that will dicate the timeframe."
Shelley said he plans to visit Moscow before the end of June for another round of meetings on the lunar mission.
If there is sufficient demand, Space Adventures and Energia plan a series of lunar expeditions.
Shelley described the two depositors as "independent customers" who booked their flights separately. He did not disclose the identities of the clients.
The moon mission requires technical upgrades to the Soyuz, and Shelley would not say if the passengers' payments would cover all the engineering work, or if the project needed additional financial investments from Russia.
Space Adventures' captive market is in tourist flights to low Earth orbit a few hundred miles above Earth, and Shelley said the supply of seats to the International Space Station is poised to go up in the next few years.
Even with the $52 million price tag per seat, tourists are paying less than NASA astronauts to get to the space station. Shelley said that is because NASA buys more training and other services than a civilian passenger needs.
"As far as when it's going to get cheaper, I really don't know," Shelley said. "We've just got to focus on trying to get enough supply into the market to meet the demand that right now is out there."
Space Adventures has a partnership with Boeing Co. to put tourists in its CST-100 crew capsule if NASA gives it the green light to fly to the space station. Boeing is competing against SpaceX and Sierra Nevada Corp. for government funding under NASA's commercial crew program, an initiative aimed at developing privately-owned space taxis, and the space agency plans to decide which companies will continue to receive federal money later this summer.
Since the end of the space shuttle program, NASA astronauts can only get to the space station on Russian Soyuz vehicles, taking up seats that Space Adventures once sold to tourists.
With the possibility of tourist flights on Boeing's CST-100 spacecraft and future openings aboard Soyuz capsules, Shelley says the price of a tourist trip to low Earth orbit could decrease after 2017.
He expects a round-trip flight on Boeing CST-100 capsule will sell for less than the $52 million quote Space Adventures has publicized for Soyuz seats.
"Hopefully, if NASA can get its own astronauts up to the space station, some seats on Russian vehicles will free up, and I think then you'll start to see some movement on price," Shelley said. "But I don't want to focus on price as the limiter on the marketplace because I don't think it is at the moment."
Sarah Brightman will take an empty Soyuz seat next year freed up by a planned one-year expedition on the space station by astronaut Scott Kelly and cosmonaut Mikhail Kornienko. Russia will still launch Soyuz spacecraft to the space station four times during the year-long expedition to ensure the crew has lifeboats for return to Earth in case of an emergency, making a seat open for Brightman.
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