Possible visibility of Virgin Orbit launch from the UK on January 9th

Home Forums General Discussion Possible visibility of Virgin Orbit launch from the UK on January 9th

Viewing 20 posts - 1 through 20 (of 25 total)
  • Author
    Posts
  • #615009
    Nick James
    Participant

    The first ever satellite launch from UK soil is now scheduled for 2023 January 9 (between 22:16 and 24:16) with a backup window on January 18. The LauncherOne rocket is carried on a pylon under the wing of a 747 which will take off from Newquay Airport (aka Spaceport Cornwall). The rocket will be released off the southwest coast of Ireland. The first stage burns for around three minutes and the second stage for around six minutes in order to deliver the payload of small satellites into a Sun-synchronous polar orbit. The vehicle will be in the Earth’s shadow throughout the ascent but the rocket exhaust may be visible from Ireland and SW England. It may be possible to see the ascent from further afield if you know where to look.

    Virgin Orbit have published some visibility maps here:

    https://virginorbit.com/the-latest/where-can-i-spot-the-launcherone-rocket-on-launch-day/

    and Dr. Marco Langbroek has posted more information on Twitter here:

    https://twitter.com/Marco_Langbroek/status/1610671534980435970

    It is just over 50 years since the UK launched Prospero into orbit using the Black Arrow rocket but that was from Australia.

    #615010
    Grant Privett
    Participant

    Sounds fun to me. Now, we just need a launch time…. 2 hours is a long time to just hang about. Suddenly a meteor camera looks very useful.

    #615022
    Grant Privett
    Participant

    The article on the Beeb suggests there is a live stream….

    https://www.youtube.com/watch?v=5Co18HcyqHk

    I will make sure I am ready from 22:30 onward.

    Has anyone any feel for how high it would be above the horizon?

    Weather looks decidedly iffy here.

    #615025
    Nick James
    Participant

    There is lots of useful technical information in the VO Service Guide here:

    https://virginorbit.com/wp-content/uploads/2020/09/LauncherOne-Service-Guide-August-2020.pdf

    On page 22 there is a launch profile diagram showing altitude (in 1000 ft) vs time. We also have the visibility maps here:

    https://virginorbit.com/the-latest/where-can-i-spot-the-launcherone-rocket-on-launch-day/

    I am assuming these mean that the vehicle is above the horizon from a particular location so they are very optimistic in terms of visibility. For example at 300s after drop the second stage will be burning and the altitude will be around 500,000 ft or 150km. At 300s according to the launch track it will be around 1000km great circle distance from Salisbury (off the northwest coast of Spain) so a bit of trigonometry gives a height above your horizon of 4 degrees I think.

    You might want to check that maths. It is a bit early in the morning…

    #615027
    Nick James
    Participant

    The attached plot should allow you to determine the visibility at your location. Use the ground track and launch profile plots to determine the altitude and great circle distance from your observing site and the curves show how far above the horizon the launcher will be. For example if it is 1000 km away and 150 km in altitude it will be around 4 degrees above your horizon.

    First stage burnout (MECO) is at around 180s and occurs at an altitude of around 75km. For the far southwest tip of Cornwall the ground track shows a great circle distance of around 450km. This corresponds to an elevation of around 10 deg above the horizon so the first stage should be visible from Cornwall if the weather cooperates. The visibility from SW Ireland is similar.

    If anyone gets any video or images please send them to me. I can include them in the Sky Notes at the next meeting.

    Attachments:
    #615030
    Alex Pratt
    Participant

    When I heard about UK Spaceports I envisioned mini versions of the Kennedy Launch Complex. I believe that the Scottish spaceports will be vertical launches, whereas the Cornwall spaceport will release a rocket from under the wing of a 747 aircraft. These first launchers are for putting CubeSats and similar small payloads into Earth orbit, joining the growing number of launch service providers.

    It’s good if this provides training and careers for UK engineers and scientists, although we’ll have to rely on NASA, SpaceX, ESA, et al for mainstream heavy lifting to the ISS, the Moon and deep space.

    A recent manned flight to the edge of space was investigated by the FAA as to whether it deviated from its approved flightpath. Let’s hope we don’t start dropping any debris onto our friends in France, Portugal, Norway…

    Alex.

    • This reply was modified 3 weeks, 3 days ago by Alex Pratt.
    #615032
    Nick James
    Participant

    Yes, the spaceports in the Highlands and islands will be for vertical launches unlike the air launch approach adopted by Virgin Orbit. They are all currently aiming for 300 kg or so to polar LEO. You can do a lot with that mass these days. They are also looking at being able to insert small payloads into heliocentric orbit so missions to the Moon and other planets are possible with these small launchers. You only need really big stuff for people!

    For the UK vertical launch vehicles have a look at Skyrora and Orbex:

    https://www.skyrora.com/
    https://orbex.space/

    Skyrora in particular are using a very British set of propellants (Hydrogen Peroxide and RP-1 kerosene). These were used in the Black Arrow launch of Prospero 50 years ago.

    It is not just careers and training, it is a potentially huge and very lucrative business.

    Regarding range safety the mission planning ensures that there is a very low probability of debris hitting anyone. The CAA wouldn’t licensed the launches otherwise.

    #615033
    Dr Paul Leyland
    Participant

    The attached plot should allow you to determine the visibility at your location. Use the ground track and launch profile plots to determine the altitude and great circle distance from your observing site and the curves show how far above the horizon the launcher will be. For example if it is 1000 km away and 150 km in altitude it will be around 4 degrees above your horizon.

    First stage burnout (MECO) is at around 180s and occurs at an altitude of around 75km. For the far southwest tip of Cornwall the ground track shows a great circle distance of around 450km. This corresponds to an elevation of around 10 deg above the horizon so the first stage should be visible from Cornwall if the weather cooperates. The visibility from SW Ireland is similar.

    If anyone gets any video or images please send them to me. I can include them in the Sky Notes at the next meeting.

    If I understand the map and your plot, the launcher should be coming up from the northern horizon and reach almost the zenith from here in La Palma. The north horizon is obscured to some extent (I am due south of El Roque) but I will see what can be seen.

    #615034
    David Totney
    Participant

    More stuff to fill the sky with. I’m a bit ambivalent about this.

    Telescopes: One Newtonian, three Maksutov Cassegrains, seven refractors, and a large SCT.

    #615035
    Nick James
    Participant

    The ground track from the Virgin site shows the launcher crossing La Palma at around T+ 560s. The vehicle is in the Earth’s shadow but the second stage motor will still be burning at that point (SECO is around T+ 590s). It will be over 500km up when it crosses over LP. It might be visible coming up in your north but I have no idea how bright the exhaust plume would be at that range and you have a bright Moon to contend with as well.

    Attachments:
    #615037
    Dr Paul Leyland
    Participant

    The ground track from the Virgin site shows the launcher crossing La Palma at around T+ 560s. The vehicle is in the Earth’s shadow but the second stage motor will still be burning at that point (SECO is around T+ 590s). It will be over 500km up when it crosses over LP. It might be visible coming up in your north but I have no idea how bright the exhaust plume would be at that range and you have a bright Moon to contend with as well.

    Thanks. I think there is a fair chance here and I have tipped off a few locals with an interest in astronomy, including a pointer to this discussion.

    Nothing we can do about the moon but perhaps wide-field binoculars may help; the lack of daylight will definitely help. I’m certainly going to give it a try, weather permitting.

    #615043
    Grant Privett
    Participant

    Using the graph Nick kindly provided of apparent elevation versus range, plus the ground path and flight profile I got some approx values.

    If I am viewing the map right, the lat and lon lines are at 2 deg spacing, I get a position for the launcher as 37N 15.5W at T+480s and 32.5N 16.5W at engine cutout.

    From Salisbury it looks like 200-300s after launch gives an altitude just under 4 degrees – rubbish, but just doable*from a high location on a good night, if the engine burn is very bright (who knows?). Okay, its a chance in a million.

    From Lands End it is better – but still not great – at ~9 degs elevation at ignition +200s. Should be brighter though.

    For Tenerife – I know someone out there currently. I get:
    T+480s ~5 degs elevation at 160km alt, 970km distant with 0 deg bearing.
    T+570s ~16degs elevation at 160km alt, 465km distant with 1 deg bearing.

    For La Palma – for Paul
    T+480 ~5 degs elevation at 160km alt, 950km distant with 13deg bearing.
    T+570 ~18degs elevation at 160km alt, 442km distant with 17deg bearing.

    I think I got that right… but some of the measurements have an element of handwavium.

    Thanks again to Nick for the visibility map. I shall hang on to a copy of that.

    #615045
    Nick James
    Participant

    Grant/Paul,

    Yes, ignore my comment about it being 500 km up over LP. I forgot that the altitudes in the flight profile plot are kft. 500 kft = 152 km so at SECO it is indeed around 160 km up.

    Damned imperial/metric confusion again.

    Attachments:
    #615047
    Grant Privett
    Participant

    Why would anyone still use feet?

    #615048
    Nick James
    Participant

    It is still the standard altitude unit in aviation.

    #615064
    Duncan Hale-Sutton
    Participant

    Clear skies here in Norfolk (10 miles from Norwich on the north side). Watched from drop of rocket until 11.30 UT. Nothing seen (but then I thought the chances were low).

    Duncan.

    #615065
    Duncan Hale-Sutton
    Participant

    Unfortunately it looks like the rocket has failed and the payload did not reach orbit.

    #615066
    Dr Paul Leyland
    Participant

    I didn’t see anything from LP.

    #615067
    Nick James
    Participant

    I didn’t expect to see anything from Chelmsford but I set up a video camera with a 200mm lens looking at the horizon in the expected azimuth. Nothing detected.

    Yes, a real shame that the second stage failed well short of orbital velocity.

    #615068
    James Lancashire
    Participant

    BBC reports satellites were lost. Expensive and embarrassing 🙁
    https://www.bbc.co.uk/news/science-environment-64218883

Viewing 20 posts - 1 through 20 (of 25 total)
  • You must be logged in to reply to this topic.