Star Talk: SpaceX set to send first commercial spacecraft to the Space Station
On May 7, the first commercial spacecraft attempting to rendezvous and dock with the International Space Station is scheduled to lift off from Cape Canaveral. Until now, only space vehicles from the United States and the Soviet Union have flown to the Space Station and docked with it.
The new spacecraft is the innovation of Space Exploration Technologies, commonly known as SpaceX. It was formed in 2002 as a space transport company by PayPal co-founder Elon Musk, who personally invested $100 million in this start-up business. Daily operations are directed by company president Gwynne Shotwell, a Northwestern University mechanical engineering graduate who has become known in the press as the “Rocket Ma’am.”
SpaceX is headquartered in Hawthorne, Calif., and has doubled in size every year since its founding. This space enterprise now employs more than 1,000 people with a rocket development team in the Mohave Desert. It also has its own launch platform at Cape Canaveral.
In 2006, SpaceX secured a $278 million NASA contract to “demonstrate cargo delivery to the International Space Station with a possible option for crew transport.” SpaceX used that seed money to develop its own two-stage rocket named Falcon-9. This launch vehicle is capable of putting satellites in Earth orbit or sending SpaceX’s newly developed space capsule — the Dragon — to the Space Station.
The Falcon-9 uses nine rocket engines — also developed by SpaceX — in its first stage and one rocket engine in its second stage. Fueled by rocket-grade kerosene and liquid oxygen in both stages, this combination gives the Falcon-9 the power to put its payload into a flight path around Earth.
Dragon is a blunt-cone space capsule, noticeably similar in appearance to the capsules of the Apollo moon program. Launched atop a Falcon-9, the Dragon capsule is capable of delivering cargo, carrying up to seven astronauts, or transporting a combination of both to Earth orbit. Further, the nose cone of the Dragon vehicle is hinged and opens to expose a berthing adapter that allows the Dragon capsule to dock with the International Space Station.
On May 7, the strategy will be to launch an unmanned Dragon capsule atop a Falcon-9 rocket into Earth orbit and then begin course adjustments to align the capsule’s trajectory with the path of the Space Station. Once the Dragon’s flight path matches that of the station, it will have to show that it can safely maneuver near the station. It will conduct a series of tests that will evaluate its systems in advance of any Space Station rendezvous.
If these goals are met, the Dragon capsule will fly by the station at a distance of approximately two miles to verify that its sensors and flight systems are completely functional — all necessary for a successful approach and docking to the station. Dragon also has to demonstrate that it can safely abort an approach to the Space Station.
If events continue to go well, the capsule will make its approach to the Space Station. The station’s crew will grasp the Dragon capsule with the station’s robotic arm to maneuver it into position at the docking port, where it will be locked into place. This entire process will take a few hours.
Once the capsule is docked, the astronauts on the Space Station will equalize the pressure between the station and the capsule, open its hatches, enter the vehicle and begin unloading its cargo.
After the capsule spends about a week attached to the station, the astronauts will reverse the process, loading the Dragon with cargo for return to Earth, sealing the hatches and undocking it using the robotic arm. Dragon will return to Earth within a day and SpaceX will recover it after splashdown off the California coast.
On Dec. 8, 2010, SpaceX became the first commercial enterprise to successfully launch a spacecraft, have it orbit Earth, then re-enter the atmosphere and land safely. The flight took over three hours, flew around the Earth twice, and splashed down less then one mile from the center of its target zone in the Pacific. Such a space flight has only been achieved by five nations — the United States, Russia, China, Japan and India — as well as the European Space Agency.
For this mission, SpaceX built the most advanced heat shield ever used to return from space. Developed in under four years — and at a fraction of the cost that NASA had budgeted — the heat shield can potentially be used hundreds of times for re-entry into Earth’s atmosphere with only minor degradation each time. It can also withstand the greater heat of faster re-entry speeds, as when a spacecraft returns from the moon or someday Mars.
Elon Musk believes that the high cost of launching rockets into space is driven, in part, by unnecessary bureaucracy. His goal for SpaceX is to reduce the cost of delivering astronauts or cargo to space by a factor of 10.
During the first week of May, Venus will shine at its maximum brightness for its current appearance in the evening sky. This extremely bright planet is very high above the western horizon when it first becomes visible and is currently taking more than three hours to set.
After mid-May, however, Venus will become visible at a lower altitude each evening. Its fall will quicken as Venus nears the time when it will swing exactly between Earth and the sun. This alignment will occur during the late afternoon of June 5, an arrangement that will not happen again for 105 years.
Mars remains against the stars of Leo for May, but the position of the Red Planet shifts from the center of the constellation to its eastern border. Mars is also dimming as the distance between it and Earth is now increasing. Saturn spends May near the bright star Spica in Virgo; at the beginning of May, Saturn is in the sky for most of the night.
On Monday and Tuesday, the moon will appear near Mars. On Friday, the moon will appear below Saturn and the next day the moon will be full. A very thin lunar crescent will be in the evening sky near Venus on Tuesday, May 22, low in the west-northwest.
Richard Monda is an astronomer living in the Capital Region.