{"id":12418,"date":"2020-06-12T18:06:00","date_gmt":"2020-06-12T10:06:00","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/astronauts-say-riding-falcon-9-rocket-was-totally-different-from-the-space-shuttle\/"},"modified":"2020-06-12T18:06:00","modified_gmt":"2020-06-12T10:06:00","slug":"astronauts-say-riding-falcon-9-rocket-was-totally-different-from-the-space-shuttle","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/astronauts-say-riding-falcon-9-rocket-was-totally-different-from-the-space-shuttle\/","title":{"rendered":"Astronauts say riding Falcon 9 rocket was \u201ctotally different\u201d from the space shuttle"},"content":{"rendered":"
\"\"
A view inside SpaceX\u2019s Crew Dragon spacecraft during launch May 30. NASA astronaut Bob Behnken is seen in the foreground. Astronaut Doug Hurley is seated to the left of Behnken. Credit: NASA TV \/ SpaceX<\/figcaption><\/figure>\n

Astronauts Doug Hurley and Bob Behnken say SpaceX\u2019s Falcon 9 rocket was a \u201cvery pure flying machine\u201d as it sped their Crew Dragon spaceship into orbit, but they said they were surprised by the rougher-than-expected ride on the Falcon 9\u2019s powerful upper stage.<\/p>\n

Hurley and Behnken became the first people to ride a Falcon 9 rocket into space May 30 after lifting off from pad 39A at NASA\u2019s Kennedy Space Center in Florida. Around 19 hours later, their Crew Dragon capsule autonomously docked with the International Space Station to complete the first trip to the orbiting outpost from a U.S. spaceport since the retirement of the space shuttle in 2011.<\/p>\n

Each astronaut launched on two space shuttle flights before flying on SpaceX\u2019s Falcon 9 rocket and Crew Dragon capsule.<\/p>\n

\u201cFrom the time the engines lit, the first two-and-a-half minutes to staging was about like we expected, except you can never simulate the Gs, so as the Gs built you could certainly feel those,\u201d said Hurley, the Dragon\u2019s spacecraft commander. \u201cWhat I thought was really neat was how sensitive we were to the throttling of the Merlin engines. That was really neat. You could definitely sense that as we broke Mach 1.<\/p>\n

\u201cThe next thing you know, the call was made (as we exceeded the speed of sound),\u201d Hurley said. \u201cWe didn\u2019t even need to look at the speed. You could tell just by how the rocket felt, so it\u2019s a very pure flying machine.\u201d<\/p>\n

Hurley, a retired U.S. Marine Corps colonel, flew F\/A-18 jets as a test pilot before his selection as a NASA astronaut. Behnken, who earned a doctorate in mechanical engineering from Caltech, is a colonel in the U.S. Air Force and was a flight test engineer on the F-22 fighter jet before becoming a NASA astronaut.<\/p>\n

Both have accumulated thousands of hours of flying time on more than 25 types of aircraft.<\/p>\n

The Crew Dragon astronauts said the ride on the Falcon 9 rocket was smoother than the space shuttle for the first couple of minutes. The space shuttle launched with two solid rocket boosters, which provided more than two-thirds of the shuttle\u2019s total thrust at liftoff.<\/p>\n

\"\"
Astronauts Bob Behnken and Doug Hurley after their arrival at the International Space Station on May 31. Credit: NASA<\/figcaption><\/figure>\n

The solid-fueled boosters burned for more than two minutes, firing concurrently with the shuttle\u2019s three hydrogen-fueled main engines. The shuttle\u2019s engines continued burning after booster separation, and fired more than eight minutes until engine cutoff after placing the vehicle on a preliminary suborbital trajectory. The shuttle orbiter used smaller thrusters to reach a stable orbit around Earth.<\/p>\n

\u201cRemember, shuttle had solid rocket boosters to start with,\u201d Hurley said. \u201cThose burned very rough for the first two-and-a-half minutes. The first stage with Falcon 9 were the nine Merlin engines.\u201d<\/p>\n

The Merlin engines generated about 1.7 million pounds of thrust at full power, consuming a mix of super-chilled kerosene and cryogenic liquid oxygen propellants.<\/p>\n

\u201cIt was a much smoother ride, obviously, because it was a liquid engine ascent,\u201d Hurley said of the Falcon 9\u2019s first stage.<\/p>\n

On a space shuttle launch, astronauts said the ride became smoother after burnout and separation of the twin solid rocket boosters, once the shuttle\u2019s liquid-fueled engines took over the primary propulsion role.<\/p>\n

\u201cWe were surprised a little bit at how smooth things were off the pad,\u201d Behnken said. \u201cThe space shuttle was a pretty rough ride heading into orbit with the solid rocket boosters, and our expectation was ,as we continued with the flight into second stage, that things would basically get a lot smoother than the space shuttle did. But Dragon was huffing and puffing all the way into orbit.<\/p>\n

\u201cIt was not quite the same ride the smooth ride as the space shuttle was up to MECO (main engine cutoff),\u201d Behnken said. \u201cA little bit less Gs, but a little bit more alive is probably the best way I would describe it.\u201d<\/p>\n

\u201cWhere the differences started, I think, for both Bob and I \u2014 and we commented on it at the moment \u2014 was at staging,\u201d Hurley said. \u201cAnd it was very similar to what you saw in the Apollo 13 movie, where they staged from first to second stage. So the first stage engines shut off  \u2026 (the first stage separates) and then the Merlin Vacuum engine starts.<\/p>\n

\u201cSo at that point we go from roughly 3Gs to zero Gs \u2026 and when the Merlin Vacuum engine fires, then we start accelerating again for the next five or six minutes until we achieve orbit,\u201d he said.<\/p>\n

\u201cThat was the highlight of the ascent for me,\u201d Hurley said.<\/p>\n

\u201cSo totally different than shuttle,\u201d Hurley said. \u201cIt was smooth. It got a little rougher.\u201d<\/p>\n

SpaceX developed the Crew Dragon spacecraft under contract to NASA. The space agency is also working with Boeing on the Starliner crew capsule, which is now expected to launch with astronauts for the first time in early 2021 on top of a United Launch Alliance Atlas 5 rocket.<\/p>\n

\"\"
SpaceX\u2019s Falcon 9 rocket climbs into orbit May 30 from the Kennedy Space Center. Credit: SpaceX<\/figcaption><\/figure>\n

Hurley described the ride on the Merlin Vacuum upper stage engine as \u201ckind of like driving fast on a gravel road.\u201d<\/p>\n

\u201cSo little bit of vibration, not anything that was really unpleasant, but you certainly knew that there was powerful engine behind you,\u201d he said. \u201cAnd that took us all the way to orbit about six minutes later, and once again the Gs (built up), and how the engine throttled to control the Gs, and the engine cutoff.\u201d<\/p>\n

The G-force dropped off instantaneously as the Merlin Vacuum engine shut down, according to Hurley.<\/p>\n

\u201cWe knew we made it to orbit.\u201d<\/p>\n

The Merlin Vacuum engine produces around 210,000 pounds of thrust at peak performance, while the three shuttle main engines combined to generate more than 1.4 million pounds of thrust once in space. But the space shuttle was much larger than the Crew Dragon spacecraft and the Falcon 9 upper stage, placing the astronauts farther away from the engines.<\/p>\n

\u201cIt will be interesting to walk with the SpaceX folks to find out why it was a a little bit rougher ride on the second stage than it was for shuttle on those three main engines,\u201d Hurley said.<\/p>\n

SpaceX recorded audio, accelerations and other data on the Crew Dragon\u2019s unpiloted test flight to the space station last year. Ground teams played the audio for Hurley and Behnken, giving the astronauts a preview of what they would experience during launch, re-entry and splashdown in the ocean.<\/p>\n

\u201cThe biggest difference is just the dynamics that are involved, the vibration, the experiences that we felt actually riding a real rocket,\u201d Behnken said. \u201cGoing through the fueling operation, that was a new experience for us. The space shuttle was fueled when the astronauts arrived (at the launch pad). Doug and I went through the fueling operation on-board Dragon, which was different for us. So hearing the venting and the valve sounds and the little vibrations associated with that operation was a new experience for us.\u201d<\/p>\n

During the 19-hour trip to the space station, Hurley tested the Crew Dragon\u2019s manual control system two times, using the ship\u2019s touchscreen displays to put in manual commands for the capsule\u2019s maneuvering thrusters.<\/p>\n

\u201cFlying the Dragon was exactly how we expected it to be,\u201d Hurley said.<\/p>\n

SpaceX designed the Crew Dragon will to be fully autonomous, without requiring manual inputs from the astronauts on-board. But Dragon crews will have the ability to manually dock with the space station if necessary, and there are buttons to command a launch abort, initiate a deorbit and re-entry, and deploy parachutes if needed.<\/p>\n

\u201cIf there are any system failures or other issues, we would like to know with confidence that if we take over manually, the vehicle will do what we need it to do,\u201d Hurley said.<\/p>\n

The Dragon\u2019s automatic docking with the space station felt more gentle than expected, Hurley said.<\/p>\n

\u201cThe thing that really stood out to both us \u2014 and we mentioned it was soon as we docked \u2014 is we didn\u2019t feel the docking,\u201d he said. \u201cIt was just so smooth, and then we were docked. In shuttle, you felt a little bit of a jolt, nothing real heavy, but you felt it.\u201d<\/p>\n

Hurley and Behnken also had positive reviews for their SpaceX-made pressure suits. The astronauts wore them during launch and docking, and will put them on again for their return to Earth \u2014 expected in late July or August.<\/p>\n

\u201cThey\u2019re custom designed and custom fitted, so they\u2019re very comfortable,\u201d Hurley said.<\/p>\n

The astronauts said taking off the suits and putting them on in space, without the effect of gravity, was much easier than on Earth.<\/p>\n

\u201cWe\u2019d have to give the suits a five star rating,\u201d Behnken said.<\/p>\n

\u201cEach suit is point designed for a very specific mission,\u201d Behnken said. \u201cThis one is point designed for us to sit in our seats and protect us if there\u2019s a fire or any sort of a problem with the atmosphere on-board Dragon, (if) it\u2019s leaking out, or has smoke in it, or anything like that.<\/p>\n

\u201cThese suits didn\u2019t have to do that job for us, which was nice, but it was clear that they were ready.\u201d<\/p>\n

\u201cFor us \u2014  as the test pilots, so to speak \u2014 we\u2019re there to evaluate how it does the mission, and so far it\u2019s done just absolutely spectacularly,\u201d Hurley said.<\/p>\n

Email the author.<\/i><\/b><\/p>\n

Follow Stephen Clark on Twitter: @StephenClark1.<\/strong><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

A view inside SpaceX\u2019s Crew Dragon spacecraft during launch May 30. NASA astronaut Bob Behnken is seen in the foreground. Astronaut Doug Hurley is seated to the left of Behnken. Credit: NASA TV \/ SpaceX Astronauts Doug Hurley and Bob Behnken say SpaceX\u2019s Falcon 9 rocket was a \u201cvery pure flying machine\u201d as it sped […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[2125,524,291,235,2126,2127,2034,479],"class_list":["post-12418","post","type-post","status-publish","format-standard","hentry","category-news","tag-bob-behnken","tag-commercial-crew","tag-commercial-space","tag-crew-dragon","tag-crew-dragon-demo-2","tag-doug-hurley","tag-expedition-63","tag-falcon-9"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/12418"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=12418"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/12418\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=12418"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=12418"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=12418"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}