Featured Research

from universities, journals, and other organizations

Astronomers stumped by 'flyby anomaly': Unexplained variation in spacecraft speeds

Date:
October 9, 2013
Source:
European Space Agency
Summary:
A mystery that has stumped scientists for decades might be one step closer to solution after European Space Agency tracking stations carefully record signals from NASA's Juno spacecraft as it swings by Earth. Engineers hope that the new measurements will unravel the decades-old 'flyby anomaly' -- an unexplained variation in spacecraft speeds detected during some swingbys.

NASA's Juno spacecraft approaching Earth on 9 October 2013 (artist's rendering). NASA's deep-space probe will zip past to within 561 km of Earth at 19:21 GMT as it picks up a gravitational speed boost to help it reach Jupiter in 2016. During the high-speed event, radio signals from the 3225 kg Juno will be carefully recorded by ESA tracking stations in Argentina and Australia.
Credit: NASA

A mystery that has stumped scientists for decades might be one step closer to solution after ESA tracking stations carefully record signals from NASA's Juno spacecraft as it swings by Earth today.

Related Articles


NASA's deep-space probe will zip past to within 561 km at 19:21 GMT as it picks up a gravitational speed boost to help it reach Jupiter in 2016.

During the high-speed event, radio signals from the 2870 kg Juno will be carefully recorded by ESA tracking stations in Argentina and Australia.

Engineers hope that the new measurements will unravel the decades-old 'flyby anomaly' -- an unexplained variation in spacecraft speeds detected during some swingbys.

"We detected the flyby anomaly during Rosetta's first Earth visit in March 2005," says Trevor Morley, flight dynamics expert at ESA's ESOC operations centre in Darmstadt, Germany.

"Frustratingly, no anomaly was seen during Rosetta's subsequent Earth flybys in 2007 and 2011. This is a real cosmic mystery that no one has yet figured out."

Sometimes there, sometimes not

Since 1990, mission controllers at ESA and NASA have noticed that their spacecraft sometimes experience a strange variation in the amount of orbital energy they pick up from Earth during flybys, a technique routinely used to fling satellites deep into our Solar System.

The unexplained variation is noticed as a tiny difference in the expected speed gained (or lost) during the passage.

The variations are extremely small: NASA's Jupiter probe ended up just 3.9 mm/s faster than expected when it swung past Earth in December 1990.

The largest variation- a boost of 13.0 mm/s -- was seen with NASA's NEAR asteroid craft in January 1998. Conversely, the differences during swingbys of NASA's Cassini in 1999 and Messenger in 2005 were so small that they could not be confirmed.

The experts are stumped.

ESA stations listen for Juno

On 9 October, engineers and the flight dynamics teams at ESOC will watch closely as the Agency's new 35 m-diameter deep-space dish in Malargüe, Argentina, and a smaller 15 m dish in Perth, Australia, track Juno starting at about 16:00 GMT.

The stations will record highly precise radio-signal information that will indicate whether Juno speeds up or slows down more or less than predicted by current theories.

The results will be studied closely by ESA and NASA as well as scientists worldwide, who are hoping to see whether the anomaly is again detected.

"Our Malargüe station is designed to track very distant and relatively slow-moving spacecraft, while Juno will pass by moving very, very fast at just 561 km altitude," says ESA's Daniel Firre, responsible for the tracking support at ESOC.

"This makes tracking Juno technically very challenging, but it's how the scientific process works. Gathering more data that can be analysed by experts is critical if we are ever to solve this perplexing mystery."


Story Source:

The above story is based on materials provided by European Space Agency. Note: Materials may be edited for content and length.


Cite This Page:

European Space Agency. "Astronomers stumped by 'flyby anomaly': Unexplained variation in spacecraft speeds." ScienceDaily. ScienceDaily, 9 October 2013. <www.sciencedaily.com/releases/2013/10/131009111111.htm>.
European Space Agency. (2013, October 9). Astronomers stumped by 'flyby anomaly': Unexplained variation in spacecraft speeds. ScienceDaily. Retrieved March 3, 2015 from www.sciencedaily.com/releases/2013/10/131009111111.htm
European Space Agency. "Astronomers stumped by 'flyby anomaly': Unexplained variation in spacecraft speeds." ScienceDaily. www.sciencedaily.com/releases/2013/10/131009111111.htm (accessed March 3, 2015).

Share This


More From ScienceDaily



More Space & Time News

Tuesday, March 3, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: SpaceX Launches Rocket, Satellites on Board

Raw: SpaceX Launches Rocket, Satellites on Board

AP (Mar. 2, 2015) — SpaceX launched it&apos;s 16th Falcon 9 rocket from Cape Canaveral, Florida on Sunday night. The rocket was carrying two commercial communications satellites. (March 2) Video provided by AP
Powered by NewsLook.com
NASA EDGE: SMAP Launch

NASA EDGE: SMAP Launch

NASA (Mar. 2, 2015) — Join NASA EDGE as they cover the launch of the Soil Moisture Active Passive (SMAP) spacecraft live from Vandenberg Air Force Base.  Special guests include NASA Administrator Charlie Bolden, SMAP Project System Engineer Shawn Goodman and Lt Col Brande Walton and Joseph Sims from the Air Force.  No word on the Co-Host&apos;s whereabouts. Video provided by NASA
Powered by NewsLook.com
Astronauts Leave Space Station for Third Spacewalk

Astronauts Leave Space Station for Third Spacewalk

Reuters - News Video Online (Mar. 1, 2015) — NASA Commander Barry Wilmore and Flight Engineer Terry Virts perform their third spacewalk in eight days outside the International Space Station. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Spacesuit Water Leaks Not An Issue On Latest ISS Walk

Spacesuit Water Leaks Not An Issue On Latest ISS Walk

Newsy (Mar. 1, 2015) — Astronauts are ahead of schedule with hardware upgrades to the International Space Station, despite last week&apos;s spacesuit water leak scare. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins