Organic revenue was up over 6%, with growth across our key end markets and all four business segments.
Funded book-to-bill was 1.0 for the quarter and 1.05 year-to-date.
Margins increased to 18.6%, resulting in earnings per share of $3.26, up 15%.
We had solid free cash flow of $685 million, which contributed to shareholder returns above $1 billion, including repurchases of $850 million in the quarter and over $1.5 billion year-to-date.
Our government businesses were up 6% in the second quarter, driven by double-digit growth internationally.
Our space business strategy is working as we grew 10% in the quarter, capturing classified awards totaling over $300 million for ground and responsive satellite solutions.
These awards are also part of the revenue synergy capture efforts and bring awards to date to over $700 million on a win rate of 70% from our growing $7 billion-plus pipeline.
Turning to our Commercial Aerospace and Public Safety businesses, they were up over 5% in aggregate and were led by our Commercial Aerospace business up double digits off a low base and from strength in product sales.
Backlog increased 7% organically year-over-year to over $20 billion, with notable award activity across all domains.
With a three year space pipeline of nearly $20 billion, there's more opportunity for continued growth.
Within the air domain, we strengthened our existing F-35 franchise with initial production awards for the Aircraft Memory System and the Panoramic Cockpit Display Electronic Unit under the TR3 program.
This brings total orders year-to-date on the platform to about $500 million.
We're progressing on all three TR3 systems through integration and qualification this year, and in support of the planned lot 15 cut in of the production hardware.
We are also secured a roughly $100 million IDIQ with SOCOM for infrared EO sensors on rotary platforms furthering our modernization opportunities across L3Harris.
First, we received a $3.3 billion five year IDIQ for foreign military sales to a range of partner countries from our new broader portfolio of products, including radios and SATCOM terminals.
This replaces our prior five year $1.7 billion contract, which supports and validates the continued modernization across geographies and expands our product scope.
Second, in the U.K., we received a logistic support contract covering legacy Bowman and future Morpheus radios, positioning us well for a $1 billion modernization opportunity in that country.
This undersea warfare training range program, called U.S. litter, has an award value of nearly $400 million and further builds our credibility to pursue additional domestic international opportunities.
In the cyber domain, while limited to what we can say due to the classified nature, our $1 billion Intel & Cyber business received over 250 million in orders for complex mission solutions and specialized communications for both domestic and international markets, leading to another quarter of book-to-bill above 1.0 for this business.
We also had a key award in an adjacent market with our Public Safety business with a 15-year $450 million contract from the state of Florida to upgrade and continue operating its law enforcement system for first responders.
For example, at SAS, the team completed a successful preliminary design review for an advanced EW solution called Viper Shield that can deliver self-protection capability for Block 70 F-16s.
And financially, we had another quarter of strong margins as the team continues to offset mix impacts from early stage programs with three key initiatives, including program excellence and factory productivity, allowing us to flow through cost synergies totaling an incremental $27 million in the quarter.
In addition, the first half synergy run rate is now $350 million, driven by progress on facilities, consolidation and IT efficiencies.
We see this as the minimum level we'll deliver on this year, up from the $320 million to $350 million range we discussed in April and still a year ahead of schedule.
On margins for the year, this leaves us at about 18.5% for the top end of the prior guide and a level we'll look to build on in the years ahead.
Today, we announced the sale of two small businesses within our Aviation Systems segment for $185 million in cash, and these should close before year-end.
When combined with the roughly $2.5 billion divested under our portfolio shaping initiative, total gross proceeds are set to be $2.7 billion.
We have now divested nearly 10% of our revenues.
Our expectation now is for buybacks to be roughly $3.4 billion this year, up versus our prior guide of $2.3 billion.
When combined with dividends, capital returns will be about $4.2 billion in 2021.
Organic revenue was up 6.2%, with a return to growth in all four segments.
IMS led the way up 12%, followed by a return to growth at AS of 4.7%.
Margins expanded 40 basis points to 18.6%, primarily from E3 productivity, program performance and integration benefits, partially offset by higher R&D.
These drivers, along with our share repurchases, led to earnings per share being up 15% or $0.43 to $3.26, as shown on Slide five.
Of this growth, volume, synergies and operations contributed $0.18, a lower share count contributed another $0.18 and pension, tax and interest accounted for the remaining $0.07.
Free cash flow was $685 million, while working capital days stood at 57 due to receivables timing.
And shareholder returns of over $1 billion were comprised of $850 million in share repurchases and $207 million in dividends.
Of note, our last 12 months of share repurchases have totaled over $3 billion at an average price of $195 per share, well below our current share price.
Integrated Mission Systems revenue was up 12%, led by double-digit growth in ISR aircraft missionization on a recently awarded NATO program.
Operating income was up 2%, while margins contracted 150 basis points to 15.3%, reflecting expected mix impacts, including a ramp on growth platforms and programs.
Pointed book-to-bill was 0.81 in the quarter and 1.06 for the first half with strength across the segment.
In Space and Airborne Systems, organic revenue increased 3.2% from our missile defense and other responsive programs, driving 10% growth in space, along with mid-single-digit classified growth in Intel & Cyber.
This strength outweighed the impact from modernization program transitions in our airborne businesses, the F-35 Tech Refresh three program within Mission Avionics and F-16 Viper Shield advanced electronic warfare system.
Operating income was up 7.7%, and margins expanded 90 basis points to 19.7% as operational excellence, including program performance, increased pension income and integration benefits more than offset higher R&D investments.
Next, Communication Systems' organic revenue was up 3.2% with mid-single-digit growth in Tactical Communications that included international up double digits, driven primarily by modernization demand from Asia Pacific and Europe and an anticipated decline in DoD from last year's second quarter 40%-plus growth.
And public safety was down 7% from residual pandemic-related impacts.
Operating income was up 8.3% and margins expanded 170 basis points to 25.5% from higher volume, operational excellence and integration benefits.
And funded book-to-bill in the quarter and first half were about 1.3% and 1.1%, respectively.
Finally, in Aviation Systems, organic revenue increased 4.7%, driven primarily by our commercial aerospace business that was up 20% from recovering training and air transport OEM product sales.
Operating income was up 17% and margins expanded 200 basis points to 14.5% from operational excellence, integration benefits and higher volume.
Funded book-to-bill was about 0.9 for the quarter and first half.
Overall, organic revenue growth is unchanged at 3% to 5%, with our top line trending as expected at 4% for the first half and supported by a 1.05 funded book-to-bill year-to-date.
We have raised our outlook to approximately 18.5%, a 25 basis point increase to the top end of the previous range, due to our strong performance to date and confidence in our ability to execute on cost synergies, E3 and program deliverables.
On EPS, we're raising our full year guide to a range of $12.80 to $13, with the midpoint now toward the upper end of our previous range and reflecting 11% growth from 2020, delivering on our double-digit commitment in spite of dilution from divestitures.
As shown on Slide 11, the increase of $0.05 from the prior midpoint is driven by $0.13 improvement in operations and synergies and $0.19 from a lower share count at 203 million shares, along with a lower tax rate of about 16%, all of which more than offset divested earnings of $0.31.
On a stand-alone basis, we expect about $0.15 of net dilution from divestitures.
Our guide of $2.8 billion to $2.9 billion is intact, despite divestiture-related headwinds are roughly $80 million.
It continues to reflect the three day working capital improvement from year-end to around 49 and 50 days.
capex is expected to be about $365 million, $10 million lower versus the prior guide due to completed divestitures.
Our guidance also now reflects approximately $3.4 billion in share repurchases, an increase of $1.1 billion from our prior guide to account for net proceeds from recently closed divestitures.
All told, we expect to return about $4.2 billion to shareholders this year.

Summary:
Margins increased to 18.6%, resulting in earnings per share of $3.26, up 15%.
On margins for the year, this leaves us at about 18.5% for the top end of the prior guide and a level we'll look to build on in the years ahead.
IMS led the way up 12%, followed by a return to growth at AS of 4.7%.
These drivers, along with our share repurchases, led to earnings per share being up 15% or $0.43 to $3.26, as shown on Slide five.
On EPS, we're raising our full year guide to a range of $12.80 to $13, with the midpoint now toward the upper end of our previous range and reflecting 11% growth from 2020, delivering on our double-digit commitment in spite of dilution from divestitures.