SpaceX's dull cargo run to the space station featured an exciting secondary mission: the first-ever attempt to land the booster rocket on a floating spaceport drone ship for recovery and reuse. The Falcon 9 hit the barge too hard, impacting rather than landing, a failure so close to success it's worthy of celebration.
Falcon 9 blasting off with the Dragon at 4:47 a.m. EST on Saturday morning. Image credit: NASA/Jim Grossmann
This cargo run has been attempting to get off the ground for months, with the most recent delay caused by the upper stage Z actuator behaving strangely. After swapping out a part, the SpaceX Falcon 9 rocket and finally launched early this morning from Cape Canaveral Air Force Station's Space Launch Complex 40. The rocket boosted the Dragon reusable spacecraft into orbit where it will chase down the International Space Station. You can replay the launch here:
After shedding the Dragon space capsule, the Falcon 9 rocket booster performed a controlled reentry and attempted a soft landing on the deck of the autonomous spaceport drone ship in the Atlantic Ocean. This was the first ever attempt by any space program to attempt a barge landing, with predictions for success listed at a bare 50%. While we've done plenty of soft-landings on other planets, this is the first attempt at a vehicle leaving the atmosphere, reentering, and (attempting) landing vertically on a hard surface. The attempt almost worked: the booster reached the barge, a tiny speck of artificial land in a vast ocean, but was coming too fast so the result was more "impact" than "landing." While it sounds funny to call a crash "almost successful," even reaching the barge at all required increasing the rocket's accuracy compared to past flights.
The rocket reached the autonomous spaceport drone ship, but at a speed too fast to be useful. Image credit: SpaceX
Between darkness and fog, the video of the landing attempt is uninformative:
While SpaceX has successfully soft-landed their Falcon 9 rockets on the ocean before (and on land during test flights), they recently upgraded the grid fins to allow better control and accuracy in order to hit the relatively tiny barge-target. From initial analysis of the telemetry, it appears the new grid fins worked well during the flight from hypersonic to subsonic velocities, but that the new setup was a bit more demanding than expected and the system ran out of hydraulic fluid just before landing. While hydraulics are usually closed systems that don't consumer the fluid, the grid fins operate as an open system that only functions for a few minutes. The flight had enough hydraulic fluid to run the gear 4 minutes, about 10% less time than required. This was an incredible first attempt, even if the spaceport is now covered in rocket-shrapnel and will require a bit of refurbishing to replace trashed support equipment.
With several more SpaceX launches scheduled for 2015, it's hopeful that the engineers will learn from this and get closer to an unmitigated success on the next attempts. The next mission of launching the Deep Space Climate Observatory (DSCOVR) at the end of this month already has 50% more hydraulic fluid on-board, increasing the rocket's odds for a successful barge landing, but softer this time. If SpaceX gets the wrinkles sorted out and start successfully landing instead of crashing into their floating spaceport, the long-term plan is to refuel the rocket boosters on the barge then send them on a quick hop back to the mainland for refurbishing and reuse. This will theoretically improve the economics of spaceflight, making SpaceX the only rocket manufacturer reusing their booster rockets.
Meanwhile, the Dragon space capsule successfully separated and spread its solar panels to carry food and supplies to the space station.
The deployed solar panel on the Dragon space craft produces over 5 kW of power.
Everything about the Dragon's telemetry and behaviour was so on-target perfect that NASA cancelled its post-launch briefing. Its pursuit of the station will take two days, coming within grappling range of the Canadarm early on Monday morning. Astronaut Barry "Butch" Wilmore will mate the Dragon to the Harmony capsule, where it will stay for approximately a month as it is unloaded and reloaded before it detaches, reenters, and splashes down in the Pacific Ocean.
The delays allowed some late loads to the Dragon cargo payload. Image credit: NASA
The cargo run is carrying the usual mix of astronaut care packages, station hardware, and scientific supplies. The scientific payload includes the Cloud Aerosol Transport System. CATS combines everything the internet loves — Cats, Space, and Lasers — focused on a topic sure to cause endless debates: monitoring climate change. The new instrument will be mounted on the outside of the space station, using its lasers to measure clouds and tiny particles as an effort to better understand weather systems and get another stream of data for evaluating climate change. Other parts of the science payload include a new fruit fly setup to experiment with how spaceflight impacts the immune system and the risk of in-flight infections.