Anomalous Spacecraft Acceleration (Pioneer Effect)  

In General > s.a. tests of general relativity with orbits.
* 2001: Seen in Pioneer 10/11 data, value aP = (8.74 ± 1.25) × 10–8 cm/s2, directed toward the Sun.
* 2002–2004: Blueshift of frequency of (5.99 ± 0.01) × 10–9 Hz/s, interpreted as an additional acceleration (8.74 ± 1.33) × 10–8 and (8.60 ± 1.34) × 10–8 cm/s2, no consensus yet on explanation despite a persistent interest.
* 2005: Older Pioneer tracking data will be reanalyzed in search of earlier signs of this effect.
* 2007: The cause remains unknown, although radiant heat remains a likely origin; Improved bounds on violations of Newton's second law.
* 2008: Anomaly of 13 mm/s seen in NEAR asteroid rendezvous spacecraft; JPL scientists working on analysis of Rosetta spacecraft.
* 2009: The cause remains unknown, although radiant heat remains a likely origin.
* 2011: Asymmetric radiant heat appears to be the most likely origin.
* 2012: Anisotropic thermal radiation is confirmed as the explanation for the effect [@ blog ps(12)apr]; Alternative proposal based on asymptotically FLRW model.
* Objects in which it has been seen: Pioneer 10 & 11 spacecraft, NASA's Galileo and the joint ESA-NASA Ulysses spacecraft; But not on the Voyaget 1 & 2, because they are three-axis stabilized, as opposed to spin-stabilized, and their thrusters introduce additional accelerations that overwhelm this tiny effect (and also not on planets or minor planets!); NEAR.
@ Overviews: Martin Nieto et al AIP(05)gq/04 [and tests]; Turyshev et al pw(04)sep, gq/05-proc, EAS(06)gq/05, IJMPD(06)gq/05; Martin Nieto & Anderson CQG(05)gq [and early data], CP(07)-a0709 [rev]; Reynaud & Jaekel IJMPD(07)gq/06 [and modified gravity]; Martin Nieto epn(06)gq/07; Turyshev ps(07); de Diego RMAA-a0807-conf; de Diego & Núñez RMCG-a0807-in; Turyshev & Toth SSR(09)-a0906 [new data, and New Horizons], LRR(10)-a1001 [rev].
@ Analysis: Anderson et al PRL(98)gq + pn(98)sep, PRD(02)gq/01; Turyshev et al gq/99-conf; Markwardt gq/02/PRD; Toth & Turyshev CJP(06)gq [status]; Unzicker & Schmidle gq/07 [code for quick check]; Turyshev & Toth a0710-conf, AIP(08)-a0710; Levy et al ASR(09)-a0809 [periodic anomalies]; Toth IJMPD(09)-a0901 [independent analysis]; Turyshev et al PRL(11) [time variation].
@ And other objects: Iorio & Giudice NA(06)gq [not for outer planets], in(08)gq/06 [Lense-Thirring for MGS, and outer planets], gq/06 [Uranus, Neptune, and Voyager 2]; Iorio JGPO(07)-a0712 [Jupiter and Saturn]; news pn(08)feb [NEAR asteroid rendevous spacecraft]; Iorio IJMPD(09)-a0806; Iorio MNRAS(10)-a0912 [Neptune satellites]; Bertolami et al PRD(14) [Cassini spacecraft].
@ Proposed tests: Anderson et al IJMPD(02)gq; Martin Nieto & Turyshev CQG(04)gq/03; Rathke ap/04-conf [Pluto orbiter]; Turyshev et al ASR(07)gq/04; Bertolami & Páramos gq/04-conf [rev], IJMPD(07)gq-conf [mission]; Page et al ApJ(06)ap/05 [using minor planets]; Izzo & Rathke JSR(06)ap/05 [options]; Dittus et al ESA-gq/05-conf; Martin Nieto PLB(08)-a0710 [New Horizons].
> Online resources: see Planetary Society page.

Proposed Explanations > s.a. brans-dicke phenomenology; Conformal Gravity.
@ General references: Anderson et al PRL(99)gq, PRL(99)gq [responses]; Mbelek & Lachièze-Rey gq/99/PRD [scalar field]; Crawford ap/99/PRL [interactions of traveling signals]; Rosales FP(06)qp/05 [cosmological geometric phase]; Tangen PRD(07)gq/06 [motion is non-geodesic].
@ Heat, radiation: Katz PRL(99)gq/98; Murphy PRL(99)gq/98; Scheffer PRD(03)gq/01, gq/01 [anisotropic]; news S&T(08)apr; Bertolami et al PRD(08)-a0807, SSR(10)-a0809-conf; Francisco et al PLB(12)-a1103 [modeling the reflective thermal contribution]; Rievers & Lämmerzahl AdP(11)-a1104; Turyshev et al PRL(11) + prf(11)aug [most likely asymmetric heat radiation], PRL(12)-a1204 [anisotropic thermal radiation]; Bertolami et al a1211-proc, Modenini & Tortora PRD(14)-a1311 [the whole anomalous acceleration can be explained by thermal effects].
@ Kuiper Belt gravity: de Diego et al IJMPD(06)ap/05; Martin Nieto PRD(05)ap, Bertolami & Vieira CQG(06)ap/05 [no].
@ Other conventional physics: Guruprasad ap/99 [gravitational tides on spacecraft]; Østvang CQG(02)gq/99 [coordinates]; Anderson et al MPLA(02)gq/01; Ostermann gq/02 [not non-conventional]; Anderson & Mashhoon PLA(03)gq [not helicity-rotation coupling]; Mbelek & Michalski IJMPD(04)gq/03; Mbelek gq/04 [general relativity + quintessence]; Quevedo AIP(05)gq [not solar quadrupole moment]; Martin Nieto et al PLB(05)ap [not interplanetary matter]; Hall PLB(07) [charge drag]; Mbelek a0809 [special-relativistic kinematics]; Carloni et al PRD(11)-a1103 [not Rindler acceleration].
@ Modified gravity: Moffat gq/04, Brownstein & Moffat CQG(06)gq/05 [non-symmetric], comment Iorio gq/06; Jaekel & Reynaud in(06)gq/05, comment Iorio gq/06, gq/06 [2 scale-dependent constants]; Trenčevski & Celakoska gq/06 [time-dependent potential]; Iorio FP(07)gq/06 [and planets]; Exirifard CQG(09)-a0708 [evidence against]; Avramidi & Fucci GRG(08)-a0802, CJP(09)-a0811 [matrix gravity, non-commutative]; Yefremov G&C(09); Siutsou & Tomilchik a0908 [modified metric].
@ 5D physics: Belayev gq/02; Tsipenyuk & Belayev gq/03; Gerrard & Sumner a0807.
@ Other new physics: de Souza gq/01, gq/01 [discrete fields]; Foot & Volkas PLB(01)hp [mirror matter]; Bertolami & Páramos CQG(04)gq/03 [bimetric theory on brane]; Krogh ap/04 ["quantum mechanical theory of gravity"]; Anania & Makoid ap/05/AP [bending of gravity]; Carmeli et al IJTP(06)gq/05 [and minimal acceleration]; ten Boom gq/05; Mbelek et al EPL(07)ap/06 [non-linear electrodynamics]; McCulloch MNRAS(07)ap/06 [modified inertia]; Castro FP(07), PLB(09) [Weyl geometry]; Tomilchik a0704 [kinematical effect of conformal invariance]; Zaveri a0709 [proper time drift]; Li & Chang PLB(10)-a0909 [Randers-Finsler geometry]; Castro IJMPA(10) [Clifford-space approach]; ten Boom a1205.
@ Variation in speed of light: Ellman gq/98; Rañada EPL(03)gq/02, gq/04; Shojaie CJP(12)-a1005.
@ Cosmology: Rosales & Sánchez-Gómez gq/98; Rosales gq/02; Nottale gq/03 [cosmological constant]; Rosales gq/04 [Berry phase]; Rañada FP(04)gq, Rañada & Tiemblo gq/06 [clock acceleration], a0804, a0909 [quantum cosmology and clock desynchronization]; Palle APS(05)ap/04; Trencevski GRG(05)gq/04; Oliveira IJTP(07)-gq/06; Fahr & Siewert gq/06; Scholz ap/07/PRD; Lachièze-Rey CQG(07)gq [no]; Wilson & Blome ASR(09)-a0908 [not universal rotation]; Shojaie a1201 [universal expansion, perturbed FLRW metric]; Ferreira ASR(12)-a1202 [locally anisotropic expanding metric]; Kopeikin PRD(12)-a1207 + news R&D(12)oct [celestial dynamics of particles and light in an asymptotically FLRW universe]; > s.a. test-body orbits.

Related Topics > s.a. Flyby Anomalies.
@ References: Defrere & Rathke gq/05-conf [and gravitational wave detection]; Turyshev AJP(05)nov [problem set]; Letter and reply Morris AJP(06)may, Turyshev et al AJP(06)may; Hodge ap/06 [scalar potential model]; Mäkelä a0710 [hypothesis based on numerical coincidence]; Feldman & Anderson IJMPD(15)-a1506 [on the possible onset].

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